U-boat Archive - BDU KTB PG30324

F.d.U./B.d.U.'S War Log

16 - 31 May 1943

PG30324

16.May 1943

I.	U 66	-	CD 38	U 209	-	BF 45	U 402	-	BD 91	U 603	-	BD 26
	67	-	BE 83	211	-	BE 66	403	-	BD 65	607	-	BD 64
	91	-	Op(AJ 39)	217	-	BE 24	405	-	BE 66	608	-	BF 83
	92	-	Op(AJ 35)	218	-	Op(AK 46)	413	-	Op(AK 42)	614	-	BD 81
	103	-	BD 67	221	-	BD 26	418	-	Op(AK 35)	621	-	BD 68
	105	-	ET 76	223	-	BE 79	436	-	BD 91	628	-	BE 66
	107	-	BD 83	226	-	BF 58	447	-	CG 90	634	-	BD 66
	109	-	Op(AJ 35)	227	-	Op(AJ 32)	448	-	BD 91	636	-	Op(AD 92)
	119	-	BD 83	228	-	BD 26	454	-	BD 91	640	-	Op(AD 97)
	123	-	ES 89	229	-	BE 58	459	-	BD 91	641	-	BE 56
	126	-	ES 99	230	-	BD 66	460	-	ES 57	642	-	BD 26
	128	-	Op(CD 41)	231	-	BD 83	461	-	BD 26	645	-	Op(AJ 32)
	129	-	CD 41	232	-	AE 67	463	-	BF 71	646	-	AE 69
	154	-	Op(FJ 60)	258	-	Op(AJ 35)	466	-	BD 91	648	-	BF 46
	161	-	Op(CA 90)	260	-	BE 54	468	-	BD 83	650	-	BD 68
	168	-	BF 44	262	-	CD 36	504	-	BD 83	657	-	Op(AD 97)
	176	-	Op(DN 40)	264	-	Op(AK 42)	511	-	BD 65	659	-	CG 90
	177	-	Op(GR 90)	266	-	BE 66	514	-	BD 65	662	-	BF 44
	178	-	Op(KZ 70)	267	-	BE 46	515	-	EV 78	664	-	Op(AJ 39)
	180	-	Op(KY)	273	-	AE 69	521	-	BE 76	666	-	BD 26
	181	-	Op(KP 60)	304	-	Op(AJ 32)	525	-	BD 64	707	-	Op(AJ 39)
	182	-	CF 89	305	-	BE 68	527	-	BE 84	709	-	BD 91
	190	-	BC 93	336	-	BD 38	533	-	BD 68	731	-	Op(AD 96)
	193	-	AF 76	340	-	Op(AD 96)	552	-	Op(AK 42)	752	-	BD 65
	195	-	GQ 24	358	-	BF 64	558	-	BD 38	760	-	Op(AD 92)
	196	-	Op(KZ 20)	359	-	BE 79	569	-	BD 91	951	-	AN 31
	197	-	FM 81	377	-	BD 92	575	-	BD 67	952	-	Op(AJ 35)
	198	-	Op(KP 80)	378	-	Op(AK 42)	584	-	BD 81	953	-	AN 31
	199	-	AN 31	381	-	Op(AJ 35)	591	-	BF 58	954	-	Op(AJ 35)
	202	-	Op(AJ 39)	383	-	BD 81

	On Return Passage: U 103 - 105 - 107 - 123 - 126 - 129 - 168 - 182 - 209 - 223 - 226 - 230 - 260 - 262 - 266 - 267 - 358 - 359 - 383 - 402 - 405 - 454 - 466 - 504 - 514 - 525 - 533 - 584 - 614 - 628 - 634 - 648 - 634 - 648 - 662 - 709.
	Entered Port: U 358 - St. Nazaire.
	Sailed: - . -

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 40 see IVa.
		2)	Situation reports:
			U 128: Sighted 7th May in FQ 4142 coastal vessel with escort, course S, 11th May in FJ 8756 single vessel, course 130⁰ 12 knots, lost sight of owing to change of course in rain squall. Nothing sighted off Bahia up to 15th May. FQ 2227 air activity, FJ 6773 aircraft bombs.
			U 154: Nothing sighted from 2nd May over FK 10, 40, FJ 59 - 38 and along the coast, apart from neutral traffic. Plug shot on "Motorearline", 8,917 GRT, course 180⁰, on 8th May in FK 6238. Detonation after 4 hours. Subsequently driven off by continuous air activity by day and in the middle of the night

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			with depth charges, on one occasion 8 depth charges by a "Catalina". Nothing sighted while searching for traffic in FJ 39 over FC 74 and 73 to 55, apart from continuous day and night air activity.
			U 105: "Maroussio-Logothetis", 4,669 GRT, bound from Rio via Freetown to England, sunk on the 15th May in ET 5997. While hauling ahead driven off twice by a "Catalina".
			U 181: "Tinhow", 5,232 GRT, sunk on 11th May in KP 4777. Since then in KP 53 only a small amount of neutral traffic. Moderate sea and air patrol.
	b)	None.
	c)	1)	U-boat sightings: DM 55, FC 53 and a further 6 sightings approximately in the Biscay latitude.
		2)	U-boat attacks in BB 4563 and FJ 59.
		3)	Location of a wreck in DM 1678 (U 176?).
	d)	None.

IV.	Current Operations:
	a)	Convoy No. 40: The expected convoy ONS 7 has not arrived up to now. Group "Iller" and "Danube 1 and 2" proceeding south-westward will be ordered to remain at 1400 in the position line reached from AD 9642 to AK 4653 as a patrol line. As from 1500 arrival of the HX 238 convoy may be expected according to a special intercept message. (See War Diary of 14th May).
	b)	None.
	c)	1)	U 447 and 659 will be permitted to move away westward if passage through the Straits of Gibraltar has not yet been possible.
		2)	U 584 - 614 and 383 have refueled from U 119 for return passage. U 119 will proceed further for special operation Halifax.
		3)	U 514 has handed over reserve fuel to U 752.
	d)	None.

V.	Reports if Success:
	U 105 - 1 ship 4,669 GRT
	U 181 - 1 ship 5,232 GRT
	U 154 - 1 ship 8,917 GRT torpedoed.

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17.May 1943.

I.	U 66	-	CD 28	U 202	-	Op(AJ 39)	U 383	-	BD 68	U 591	-	BF 64
	67	-	BE 84	209	-	BF 46	402	-	BD 91	603	-	BD 26
	91	-	Op(AJ 39)	211	-	BE 65	405	-	BF 45	607	-	BD 64
	92	-	Op(AJ 39)	217	-	BD 32	403	-	BD 62	608	-	BF 82
	103	-	BD 67	218	-	Op(AK 46)	413	-	Op(AK 42)	614	-	BD 81
	105	-	Op(ET 72)	221	-	BD 26	418	-	Op(AJ 35)	621	-	BD 68
	107	-	BD 83	223	-	BE 85	436	-	BD 91	628	-	BF 45
	109	-	Op(AJ 39)	226	-	BF 64	447	-	CG 90	634	-	BD 66
	119	-	BD 81	227	-	Op(AJ 32)	448	-	BD 91	636	-	Op(AD 96)
	123	-	ES 88	228	-	BD 26	454	-	BD 91	640	-	Op(AJ 30)
	126	-	ES 88	229	-	BE 46	459	-	BD 91	641	-	BE 54
	128	-	Op(FQ 65)	230	-	BD 66	460	-	ES 88	642	-	BD 26
	129	-	CD 29	231	-	BD 83	461	-	BD 26	645	-	Op(AJ 32)
	154	-	Op(FC 53)	232	-	AE 83	463	-	BE 92	646	-	AE 67
	161	-	Op(CA 90)	258	-	Op(AJ 35)	466	-	BD 91	648	-	BF 46
	168	-	BF 55	260	-	BE 56	468	-	BD 59	650	-	BD 91
	176	-	Op(DN 40)	262	-	BD 87	504	-	BD 83	657	-	Op(AJ 30)
	177	-	Op(GR 90)	264	-	Op(AK 43)	511	-	DH 22	659	-	CG 90
	178	-	Op(KZ 70)	266	-	BF 44	514	-	BE 52	662	-	BF 45
	180	-	Op(KY 60)	267	-	BE 56	515	-	ET 98	664	-	Op(AJ 39)
	181	-	Op(KP 64)	273	-	AE 67	521	-	CF 12	666	-	BD 26
	182	-	CF 91	304	-	Op(AJ 32)	525	-	BD 64	707	-	Op(AK 42)
	190	-	CD 22	305	-	BE 51	527	-	BE 78	709	-	BD 91
	193	-	AN 23	336	-	BD 29	533	-	BD 68	731	-	Op(AD 96)
	195	-	CQ 56	340	-	Op(AD 96)	552	-	Op(AK 43)	752	-	BD 65
	196	-	Op(KZ 20)	359	-	BE 79	558	-	BD 26	760	-	Op(AD 96)
	197	-	FT 23	377	-	BD 92	569	-	BD 91	951	-	AF 87
	198	-	Op(KP 80)	378	-	Op(AK 42)	575	-	BD 67	952	-	Op(AJ 32)
	199	-	AN 24	381	-	Op(AJ 35)	584	-	BD 81	953	-	AF 87
										954	-	Op(AJ 36)

	On Return Passage: U 103 - 107 - 129 - 168 - 182 - 209 - 223 - 226 - 230 - 260 - 262 - 267 - 359 - 383 - 402 - 405 - 454 - 468 - 504 - 514 - 525 - 533 - 584 - 614 - 628 - 634 - 648 - 662 - 709.
	Entered Port: U 226 - 591 - St. Nazaire.
	Sailed: - . -

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	U 161 reports. No traffic in CA 90, 89, 88, 68 and 69. Return in view of fuel shortage.
		2)	U 634 sighted in BD 6621 two vessels with escort and aircraft, alteration to south-westerly course, high speed. Supply groups in BD warned.
		3)	U 198: reported sighting at 1400 in KP 8441 a convoy of 6 ships with southerly course and slow speed. She fired 2 two fan torpedoes on 2 large vessels, together 12,000 GRT. Sinking hydrophoned but not observed owing to defence activity. Subsequently air patrol. Commanding Officer confirmed with certainty deterrent depth charges at the convoy 2 hours after attack.

- 403 -

		4)	Convoy No. 40 see IVa.
	b)	None.
	c)	1)	U-boat sightings: AL 3828, AM 5111, AL 39, BE 51, BB 30, FC 78, FC37.
			Aircraft in the Iceland area reported 3 U-boat sightings and a depth-charge attack, probably with hits. At 2105 on the 13th May a further aircraft attacked a U-boat with depth charges.
		2)	Attack by aircraft or patrol boat in FJ 68 and FJ 59 (U 128?).
	d)	See IVa.

IV.	Current Operations:
	a)	Convoy No. 40:
		According to a special intercept message the expected convoy (ON 7) was in AJ 6663 at 2300 on the 16th May, that is W. of the patrol. According to dead reckoning it could have passed the line at 7 knots, but at 9 knots by-passed it. The latter is taken to be most likely, since U 640 reported the last enemy speed to be 10 knots and, in addition, the boats were only 15 miles apart with good visibility. In addition, according to an enemy U-boat situation report of the 15th May, the enemy surprisingly knew exactly the disposition of the Groups "Danube 1 and 2". 20 - 25 boats were estimated in the area 55 - 60⁰ N, 33 - 41⁰ W and, in addition, 5 boats in a radius of 150 miles around 60⁰ N., 35⁰ W.
		This U-boat situation report was probably the main reason for the deviation of ONS 7 and for the change in course of HX 238 also expected by the Groups. The position of the latter at 2100 on the 14th May was, according to special intercept message, AJ 7687 with course 350⁰ and proceeding with course 1⁰ as from 52⁰ 1' N. Actually its position at 1700 on the 16th May was AK 7216, course 0 to 90⁰, thereby by-passing the U-boat declared area and also the patrol line.
		Pursuit by the boats would not have been successful in view of the enemy's high speed. The operation on these two convoys is therefore concluded.
		In the same special intercept situation report mention was made of SC 130 also. The position of this convoy at 2100 on the 14th May was BC 4857, course 76⁰, speed 7.5 knots. Since, in view of earlier experiences, it is assumed that it will take the same route as the HX, Groups "Danube 1 and 2" will be sent S. to intercept it.
		Order:
		U 640 - 657 - 760 - 636 - 340 - 731 - 304 - 227 - 645 - 952 - 418 - 258 and 381 to take up patrol line at 2000 on the 18th May as new Group "Danube 1" from AK 4258 to AK 8141. Joining on to this U 954 - 92 - 109 - 202 - 664 - 91 - 707 - 413 - 952 - 264 - 378 and 218 as "Danube 2" at the same time in patrol

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		line from AK 4944 to AK 8734.
		In order to make sure and to keep a watch on the area S. of the U-boat declared area, by which passes the course of 76 ordered for convoy SC 130, boats U 221 - 666 - 558 - 752 - 336 - 642 - 603 and 228, coming from Western France or from refueling, will be disposed in a patrol line from BD 2181 to BD 2769 in order to extend the line to the S. The said boats will form Group "Oder". According to dead reckoning, the convoy may be expected approximately as from 2000. The Groups are ordered to maintain radio silence except for important tactical messages.
	b)	None.
	c)	The following have refueled:
		U 634 from U 230, U 607 from U 525, U 621 from U 533,
		U 709 - 454 - 466 - 402 - 448 - 569 and 650 from U 459,
		U 221 - 666 - 642 - 603 and 228 from U 461.
	d)	None.

V.	Reports of Success:
	U 198 - 2 ships 12,000 GRT.

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18.May 1943.

I.	U 66	-	CD 18	U 202	-	Op(AK 49)	U 402	-	BD 91	U 607	-	BD 64
	67	-	BE 80	209	-	BF 40	403	-	BD 60	608	-	BF 73
	91	-	Op(AK 81)	211	-	BF 64	405	-	BF 40	614	-	BE 46
	92	-	Op(AK 49)	217	-	BD 26	413	-	Op(AK 81)	621	-	BD 68
	103	-	BD 67	218	-	Op(AK 87)	418	-	Op(AK 45)	628	-	BF 54
	105	-	ES 95	221	-	Op(BD 21)	436	-	BD 91	634	-	BE 45
	107	-	BD 83	223	-	BE 91	447	-	CG 90	636	-	Op(AJ 38)
	109	-	Op(AK 49)	227	-	Op(AK 42)	448	-	BD 91	640	-	Op(AJ 35)
	119	-	BC 95	228	-	Op(BD 27)	454	-	BD 91	641	-	BE 41
	123	-	ES 88	229	-	BD 63	459	-	BD 97	642	-	Op(DD 24)
	126	-	ES 88	230	-	BD 66	460	-	ES 88	645	-	Op(AK 42)
	128	-	FK 41	231	-	BD 83	461	-	BD 26	646	-	AE 82
	129	-	CD 35	232	-	AL 21	463	-	BE 59	648	-	BF 40
	154	-	FC 36	258	-	Op(AK 45)	466	-	BD 93	650	-	BD 91
	161	-	Op(CB 47)	260	-	BE 65	468	-	BD 83	657	-	Op(AJ 35)
	168	-	BF 61	264	-	Op(AK 84)	504	-	BD 83	659	-	CG 90
	176	-	Op(DN 40)	266	-	BF 40	511	-	DH 54	662	-	BF 58
	177	-	Op(GR 90)	267	-	BE 65	514	-	BE 54	664	-	Op(AK 73)
	178	-	Op(KY 70)	273	-	AE 82	515	-	ET 88	666	-	Op(BD 24)
	180	-	Op(KY)	304	-	Op(AK 46)	521	-	CE 35	707	-	Op(AK 81)
	181	-	Op(KP 60)	305	-	BE 18	525	-	BE 44	709	-	BD 91
	182	-	CF 63	336	-	Op(BD 24)	527	-	CE 36	731	-	Op(AJ 39)
	190	-	CD 13	340	-	Op(AJ 39)	533	-	BE 47	752	-	Op(BD 24)
	193	-	AN 24	359	-	BE 91	552	-	Op(AK 84)	760	-	Op(AJ 38)
	195	-	GQ 68	377	-	BD 60	558	-	Op(BD 24)	951	-	AF 73
	196	-	Op(KZ 20)	378	-	Op(AK 84)	569	-	BD 91	952	-	Op(AK 42)
	197	-	FT 37	381	-	Op(AK 46)	575	-	BD 67	953	-	AF 73
	198	-	Op(KP 85)	383	-	BE 45	584	-	BE 54	954	-	Op(AK 46)
	199	-	AF 76	262	-	BD 91	603	-	Op(BD 27)


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	On Return Passage: U 103 - 107 - 123 - 129 - 182 - 209 - 223 - 260 - 262 - 266 - 267 - 359 - 383 - 402 - 405 - 454 - 466 - 504 - 514 - 525 - 533 - 584 - 614 - 628 - 634 - 648 - 662 - 709.
	Entered Port: U 168 - Lorient.
	Sailed: U 214 - Brest; U 513 - Lorient; U 488 - Kiel.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 41 see IVa.
		2)	U 648 while entering the Bay of Biscay shot down an aircraft in BF 4543.
		3)	U 262 sighted a neutral ship, course 230⁰, in BD 9862.
		4)	U 515 reported extensive air activity in FF 32.
		5)	U 198 was driven off during night attack on convoy, reported yesterday in KP 8541, by aircraft using searchlights. During the night aircraft were continuously located but none approached. During the day active sea and air reconnaissance up to 50 miles from the coast.
			U 178 was detected by two aircraft carrying lights. She suspected cooperation of air cover with convoy of U 198. (Unlikely, since positions were too far apart).
	b)	None.
	c)	U-boat sightings: AK 15 and a further one in unknown position.
	d)	None.

IV.	Current Operations:
	a)	Convoy No. 41:
		At 0043 on the 18th U 304 sighted in AK 4675 expected SC convoy. 21 boats of Group "Danube" were sent in to operate against the convoy, these being U 640, 657, 760, 636, 340, 731, 304, 227, 645, 952, 418, 258, 381, 954, 92, 109, 202, 664, 91, 707 and 413.
		During the night U 645 and 952 contacted the convoy. At 0530 the convoy was in AK 4693.
		It was proceeding, according to dead reckoning, at about 8 knots.
		The operational conditions for the boats are especially unfavorable owing to specially calm weather, wind N.W. 2-4 and short nights of 6 hours. During all the hours of darkness there is also a full moon. The operation is being continued.

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	b)	1)	New objective for U 232 - 273 and 646 is AK 44. It is intended to set up a large patrol in this area.
		2)	U 195 is to operate in the area S. of Madagascar. Passage thence making long legs, sweeps under the coast.
		3)	The attention of boats in the Capetown area is drawn to the fact that in Lourwence Marques and other harbors ships are delayed owing to U-boat danger and therefore, heavy traffic is to be expected off the harbors at times.
	c)	1)	U 403 - 377 and 436 are to refuel from U 463 in ED 5155 for further operations. Tanker reports arrival.
		2)	U 103 gave over reserve fuel to U 575; U 262 took over spare parts from U 459. U 448 will have to return, in spite of having refueled, owing to break-down of her receivers.
	d)	1)	U 182 has probably been lost - has been at sea for over 5 months. According to an intercepted message, a U-boat was bombed on the 15th May in DH 4365 by a British aircraft which scored two hits. According to dead reckoning, U 182 was in this position. She was asked for her position but did not report again after the attack. She must be considered lost.
		2)	U 214 has put out for minelaying operations off Dakar. See special Order.

V.	Reports of Success:
	U 648 - 1 aircraft.

VI.	General: (6 pages of War Diary missing)

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19.May 1943.

I.	U 66	-	CC 38	U 209	-	BF 40	U 383	-	BE 49	U 575	-	BD 67
	67	-	CF 23	211	-	BE 55	402	-	BE 72	584	-	BE 58
	91	-	Op(AK 84)	214	-	DF 46	403	-	BD 65	603	-	Op(BD 27)
	92	-	Op(AK 81)	217	-	BD 26	405	-	BP 40	607	-	BD 13
	103	-	BE 48	218	-	Op(BD 21)	413	-	Op(AK 87)	608	-	BF 71
	105	-	ES 88	221	-	Op(BD 21)	418	-	Op(AK 49)	614	-	BE 55
	107	-	BD 83	223	-	BE 93	436	-	BD 67	621	-	BD 53
	109	-	Op(AK 84)	227	-	Op(AK 49)	447	-	CG 90	628	-	BF 52
	119	-	CD 12	228	-	Op(BD 27)	448	-	BD 27	634	-	BE 54
	123	-	ES 88	229	-	BD 38	454	-	BE 73	636	-	Op(AK 45)
	126	-	ES 88	230	-	BE 46	459	-	BD 98	640	-	Op(AK 42)
	128	-	FK 16	231	-	BD 83	460	-	ES 88	641	-	BD 38
	129	-	CE 12	232	-	AL 14	461	-	BD 26	642	-	Op(BD 27)
	154	-	FD 13	258	-	Op(AK 43)	463	-	BE 57	645	-	Op(AK 49)
	161	-	CB 57	260	-	BF 44	466	-	BE 72	646	-	AE 79
	176	-	Op(DN 48)	262	-	BD 96	468	-	BD 83	648	-	BF 54
	177	-	Op(GR 90)	264	-	Op(AK 88)	488	-	AO	650	-	BD 19
	178	-	Op(KZ 42)	266	-	BF 40	504	-	BD 83	657	-	Op(AK 42)
	180	-	Op(KY)	267	-	BF 47	511	-	DH 78	659	-	CG 90


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181	-	Op(KP 64)	273	-	AL 14	513	-	BF 54	662	-	BF 64
190	-	CC 36	304	-	Op(AK 46)	514	-	BE 55	664	-	Op(AK 81)
193	-	AN 24	305	-	BD 39	515	-	ET 88	666	-	Op(BD 21)
195	-	GR 74	336	-	Op(BD 24)	521	-	CE 52	707	-	Op(AK 87)
196	-	Op(KZ 20)	340	-	Op(AK 45)	525	-	BE 54	709	-	BE 73
197	-	FT 69	359	-	BF 58	527	-	CE 61	731	-	Op(AK 46)
198	-	Op(KP 85)	377	-	BD 64	533	-	BE 49	752	-	Op(BD 24)
199	-	AF 48	378	-	Op(BD 21)	552	-	Op(AK 87)	760	-	Op(AK 42)
202	-	Op(AK 84)	381	-	Op(AK 73)	558	-	Op(BD 24)	951	-	AF 44
953	-	AF 44	954	-	Op(AK 81)	569	-	BD 58	952	-	Op(AK 49)

	On Return Passage: U 103 - 107 - 123 - 129 - 182 - 209 - 223 - 230 - 260 - 262 - 266 - 267 - 359 - 383 - 402 - 405 - 454 - 466 - 504 - 514 - 525 - 533 - 584 - 614 - 628 - 634 - 648 - 662 - 709.
	Entered Port: U 648 - 628 - Brest; U 662 - St. Nazaire.
	Sailed: - . -

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 41 see IVa.
		2)	U 229 was bombed by an aircraft in approximately BE 41. She is able to submerge up to 60 meters and requests permission to return after giving up fuel.
		3)	U 218 was detected by escorts in approximately BD 21 and forced to submerge for several hours. She is proceeding into the ordered patrol line in spite of extensive damage. Return is intended after detection of the expected convoy.
	b)	None.
	c)	1)	U-boat sightings: 5 times in AK 54, 6 times in AK 5570, twice in AK 5560 (Convoy No. 41). Also in FB 55, AL 1455, 2 not decyphered.
		2)	Depth charge attack in AK 3834 and an attack in unknown position.
	d)	1)	"Sydney Star" out of Montevideo on the 12th May, bound for the clyde over FK 4391 and DS 4212. Speed 14.5 knots.
		2)	HX 239 see IVb.

IV.	Current Operations:
	a)	Convoy No. 41:
		At midday on the 19th the weather in the area of the convoy was wind S.S.E. 4, sea 3 and visibility good. Towards evening the boats reported showers but, apart from these, visibility still good.
		Contact with the convoy was maintained the whole day and during the night of 19th - 20th, but was only reported at long intervals as the boats were not able to remain close to the convoy for very

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	long. At 0727 the convoy was reported in AK 5472 and at 0840 the next morning it was in AK 6435. Apart from the 3 boats which had already approached the convoy in the first night there were 7 further ones up to it by day and in the night of 19th - 20th.
	Several boats reported strong continual air cover over the convoy and the approach of land-based aircraft from low-lying clouds. For this reason continuous contact with the convoy was apparently not possible. In addition the boats reported good cooperation between air and escort units. 5 boats were depth charged, 2 of them very heavily.
	One boat reported the convoy to consist of 25 vessels proceeding in long formation, 4 boats attempted underwater attacks on the convoy, of which 3 were not able to approach owing to the enemy turning sharply away. Only U 92 was successful. At 0930 on the 19th she sank in AK 5491 a 6,500 GRT vessel and torpedoed a further one. The operation is being continued.
b)	According to a special intercept message, the position of HX 239 on the 18th May was BC 7295, speed 9.5 knots, course 76⁰. It had orders to steer course 37⁰ as from 8136 and course 14⁰ as from BC 5855.
	Boats in BD 10 and 20 will be sent in to detect this convoy.
	Order: U 552 - 264 - 378 - 607 - 218 - 221 - 66 - 752 - 558 - 336 - 650 - 642 - 603 - 228 - 575 - 621 - 641 - 305 - 569 - 468 and 231, as Group "Mosel" will take up position in patrol line from AJ 6417 to AK 7559 at 2000 on the 21st May. At about this time arrival of the convoy may be expected.
c)	1)	U 229 gave up part of her reserve fuel to U 377 in BD 5645. The latter will then return owing to damage. U 220 will subsequently proceed to BD 5155 and give reserve fuel over to U 463.
	2)	U 461 refueled U 217 and is now out of supplies.
d)	1)	In the enemy's situation report on U-boats of the 17th May 25 boats given in the area 55 - 61⁰ N. and 35 - 44⁰ W. The "Iller" and "Danube" patrol lines, consisting of 25 boats, in this position at the moment, therefore has been correctly detected. Aircraft location again can be the only source for this. The HX 238 convoy, expected by the Groups, has, according to special intercept information, by-passed the patrol line in the S.
	2)	U 447 and 659 were ordered on the 5th May to proceed through the Straits of Gibraltar into the Mediterranean. If possible the period of the new moon was to be made use of. In spite of orders to report the boats have not done so up to now. According to an intercept message U-boats were reported on the 8th May in the area W. of Gibraltar. Probably the boats were destroyed by aircraft or by anti-submarine groups directed on to them by the aircraft. They must be considered lost.

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V.	Reports of Success:
	U 92 - 1 ship 6,500 GRT 1 ship torpedoed.

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20.May 1943.

I.	U 66	-	CC 53	U 209	-	BF 40	U 383	-	BE 58	U 575	-	BD 12
	67	-	CF 27	211	-	BE 57	402	-	BE 82	584	-	BE 67
	91	-	Op(AK 64)	214	-	BF 47	403	-	BD 50	603	-	BD 12
	92	-	Op(AK 64)	217	-	BD 28	405	-	BF 40	607	-	AK 75
	103	-	BE 58	218	-	AK 78	413	-	Op(AK 64)	608	-	BE 56
	105	-	ES 88	221	-	AK 78	418	-	Op(AK 64)	614	-	BE 59
	107	-	BD 83	223	-	BF 71	436	-	BD 50	621	-	BD 16
	109	-	Op(AK 64)	227	-	Op(AK 64)	448	-	BE 47	634	-	BE 56
	119	-	BC 87	228	-	BD 12	454	-	BE 82	636	-	Op(AK 64)
	123	-	ES 88	229	-	BD 56	459	-	BD 98	640	-	Op(AK 64)
	126	-	ES 88	230	-	BE 56	460	-	ES 88	641	-	BD 25
	128	-	FC 98	231	-	BD 83	461	-	BD 34	642	-	BD 12
	129	-	BD 89	232	-	AK 37	463	-	BE 50	645	-	Op(AK 64)
	154	-	ES 88	258	-	Op(AK 64)	466	-	BE 82	646	-	AL 21
	161	-	CB 56	260	-	BF 45	468	-	BD 83	650	-	AK 78
	176	-	Op(DN 40)	262	-	BE 76	488	-	AN 35	657	-	Op(AK 64)
	177	-	Op(GR 90)	264	-	AK 65	504	-	BD 59	664	-	Op(AK 64)
	178	-	Op(KZ 60)	266	-	BF 40	511	-	DT 52	666	-	AK 78
	180	-	Op(KY)	267	-	BF 58	513	-	BF 49	707	-	Op(AK 64)
	181	-	Op(KP 60)	273	-	AK 38	514	-	BF 54	709	-	BE 82
	190	-	CC 37	304	-	Op(AK 64)	515	-	ET 78	731	-	Op(AK 64)
	193	-	AN 24	305	-	BD 25	521	-	CE 46	752	-	AK 78
	195	-	GR 84	336	-	AK 79	525	-	BE 56	760	-	Op(AK 64)
	196	-	Op(KZ 20)	340	-	Op(AK 64)	527	-	CE 54	951	-	AE 65
	197	-	FU 75	359	-	BF 64	533	-	BE 58	952	-	Op(AK 64)
	198	-	Op(KY 80)	377	-	BD 50	552	-	AK 71	953	-	AE 68
	199	-	AF 44	378	-	AK 75	558	-	AK 78	954	-	Op(AK 64)
	202	-	Op(AK 64)	381	-	Op(AK 64)	569	-	BD 19

	On Return Passage: U 103 - 107 - 129 - 209 - 223 - 229 - 230 - 260 - 262 - 266 - 267 - 383 - 402 - 405 - 448 - 454 - 461 - 466 - 504 - 514 - 525 - 533 - 584 - 614 - 634 - 709.
	Entered Port: U 359 - St. Nazaire.
	Sailed: U 535 - Brest; U 467 - Bergen; U 667 - Kiel.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 40 see IVa.
		2)	U 123 sighted in ES 5147 returning Spanish vessel "Eolo" course 25⁰.
	b)	None.
	c)	U-boat sightings: DN 77, AE 9190, DM 9129, AK 6367, AL 4442, AK 6561, AL 4197, AK 6672, AK 6177, AK 6417, AL 4469, 7 further ones in positions not decyphered, probably in the North Atlantic.

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		At about 60⁰ 40' North, longitude unknown, a U-boat was attacked with depth charges by aircraft.
	d)	None.

IV.	Current Operations:
	a)	Convoy No. 41:
		The weather situation in the area of the convoy became increasingly unfavorable in view of low visibility of about 3 miles, rain and rough sea. The low-hanging clouds were a great danger to the boats in view of surprise attacks by aircraft.
		Contact was no longer made with the convoy, since, in view of visibility and strong, continuous air cover the boats could not get up to it; in the night of 20th / 21st only, hydrophone fixes on the convoy were again reported from AL 6380.
		Owing to increasingly unfavorable conditions the operation against the convoy had to be broken off at midday on the 20th. Several boats were bombed heavily and it is to be assumed that enemy air defence is becoming increasingly strong all along the coast.
		Final Survey of Convoy No. 41:
		Operations against the convoy lasted from the morning of the 19th to the 20th, 21 boats operating.
		Up to the afternoon of the 19th the weather situation was comparatively favorable. Then visibility became very bad owing to rain and showers, so that Control was forced to break off operations on the 20th in view of this and of the strong air cover.
		From the second day the position was that the boats could not approach near owing to continuous air cover being too strong, and is was also not possible to maintain contact and proceed in the vicinity of the convoy owing to the continual surprise attacks from low-lying clouds. These attacks could only be attributed to a very good radar location device which enables the aircraft to detect the boat above the clouds even, and then make a surprise attack from the clouds. The amazing thing is that apparently at the time only 1 to 2 machines in all were escorting the convoy, according to intercept messages of aircraft operating. Each machine detected, however, during the whole day one boat more frequently than every quarter-hour, from which it must be concluded that the enemy's radar hardly missed a boat. With about 20 boats in the vicinity of the convoy this was quite possible, since the boats were scattered around the convoy at quite short distances apart for an aircraft.
		Several boats also reported efficient cooperation between aircraft and escorts, this being confirmed by 8 depth charge attacks in succession of which 4 were particularly heavy. 2 boats had to return owing to heavy damage.
		The loss of U 954 in the vicinity of the convoy is taken as certain as this boat reported "contact made" when up to the convoy. Possibly lost in underwater attacks. U 381 was

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		probably lost off the convoy, although she did not report being up to it. It is suspected with regard to U 657, 109 and 227 that they were lost before then; they no longer reported when up to the convoy. It is probable that U 657 was already lost off Convoy No. 40, and U 227 and U 109 in the "Danube" patrol. The only sinking in this convoy was that of a 6,500 GRT ship and torpedoing of a further one by U 92.
	b)	1)	Owing to U 229 being out of action and to the late arrival of U 218, Group "Mosel" has been ordered to take up the following new disposition. At 2000 on the 21st May the patrol line will be in position from AJ 6417 to AK 7559, boats being in the following sequence: U 552 - 264 - 378 - 607 - 221 - 666 - 752 - 558 - 336 - 650 - 642 - 603 - 228 - 575 - 621 - 641 - 305 - 569 - 468 - 231 and 218.
		2)	U 119 will have freedom of action in area CC 10 and 20. She will report the weather from there once or twice a day and will then proceed, according to the moon, independently to Halifax for a special operation.
		3)	Boats with U 460 will return after refueling, into old operational areas. These are U 105 and 125 area off Freetown, U 515 - ET 60 - EU 80; U 154 - FC 10 and 80, FJ 30 and 60 and FK 10 and 40; U 128 - FJ 80 and 90 and FQ 20. U 123 is to return.
	c)	U 123 and 126 refueled from U 460, U 107 and 504 gave over reserve fuel to U 468 and 231.
	d)	1)	U 646 has not reported since putting out of Trondheim in spite of repeated orders to do so. Aircraft in the Iceland area reported on the 17th May 3 U-boat sightings and one depth charge attack on a U-boat, with probable hit. According to dead reckoning, the position of U 646 at this time was in AE 80.
			It is therefore to be assumed in all probability that U 646 was destroyed in this depth charge attack. She must be considered lost.
		2)	U 640 reported at 0100 on the 141th May, after contact with Convoy No. 40 had been lost: "Have been bombed by Catalina, pursuit being continued."
			Later, aircraft in the Iceland area reported U-boats several times in AD 70 and several depth charge attacks. Since U 640 has not reported again in spite of instructions to do so, it must be assumed that she was destroyed by a bomb-hit. Loss is probable.

V.	Reports of Success: None.

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21.May 1943.

I.	U 66	-	CC 43	U 209	-	BF 40	U 402	-	BE 91	U 569	-	Op(AK 78)
	67	-	CF 42	211	-	BE 47	403	-	BD 51	575	-	Op(AK 74)
	91	-	Op(AK 61)	214	-	BE 93	405	-	BF 64	584	-	BE 69
	92	-	Op(AK 61)	217	-	BD 19	413	-	Op(AK 64)	603	-	Op(AK 71)
	103	-	BE 67	218	-	Op(AJ 68)	418	-	Op(AK 65)	607	-	Op(AJ 68)
	105	-	ES 88	221	-	Op(AJ 68)	435	-	BF 54	608	-	BE 54
	107	-	BE 71	223	-	BF 49	436	-	BD 51	614	-	BE 68
	109	-	Op(AL 42)	227	-	Op(AL 42)	448	-	BE 49	621	-	Op(AK 75)
	119	-	CC 23	228	-	Op(AK 71)	454	-	BE 91	634	-	BE 67
	123	-	ES 24	229	-	BD 56	459	-	BD 97	636	-	Op(AK 64)
	216	-	ES 88	230	-	BE 65	460	-	ES 88	641	-	Op(AK 76)
	128	-	FD 47	231	-	BD 13	461	-	BD 63	642	-	Op(AK 71)
	129	-	BD 97	232	-	AK 29	463	-	BE 50	645	-	Op(AK 65)
	154	-	ES 88	258	-	Op(AL 42)	466	-	BE 91	650	-	Op(AJ 69)
	161	-	CC 48	260	-	BF 40	467	-	AF 73	657	-	Op(AL 42)
	176	-	Op(DN 40)	262	-	BE 85	468	-	BD 13	664	-	Op(AK 65)
	177	-	Op(GR 90)	264	-	Op(AJ 68)	488	-	AN 29	666	-	Op(AJ 69)
	178	-	Op(KZ 41)	266	-	BF 40	504	-	BE 74	667	-	AO
	180	-	Op(KY)	267	-	BF 64	511	-	DT 76	707	-	AL 51
	181	-	Op(KP 60)	273	-	AK 02	513	-	BF 47	709	-	BE 91
	190	-	CC 28	304	-	AK 61	514	-	BF 55	731	-	Op(AK 62)
	193	-	AN 24	305	-	Op(AK 76)	515	-	ES 98	752	-	Op(AJ 69)
	195	-	GR 97	336	-	Op(AJ 93)	521	-	CD 21	760	-	Op(AK 64)
	196	-	Op(KZ 20)	340	-	Op(AL 42)	525	-	BE 65	951	-	AE 59
	197	-	GF 31	377	-	BD 56	527	-	CE 48	952	-	AL 54
	198	-	Op(KY 80)	378	-	Op(AJ 68)	533	-	BE 67	953	-	AE 59
	199	-	AE 65	381	-	Op(AL 42)	552	-	Op(AJ 62)	954	-	Op(AL 42)
	202	-	Op(AK 66)	383	-	BE 67	558	-	Op(AJ 93)

	On Return Passage: U 103 - 107 - 123 - 129 - 209 - 223 - 228 - 229 - 230 - 260 - 262 - 266 - 267 - 383 - 402 - 405 - 448 - 454 - 461 - 466 - 504 - 514 - 525 - 533 - 584 - 614 - 634 - 707 - 709 - 952.
	Entered Port: U 405 - 267 - St. Nazaire.
	Sailed: - . -

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	U 403: Pursuit of a large tanker, course 230⁰, speed 13 knots in BD 5174 proved fruitless. Operation was broken off owing to low supplies of fuel (8 cbm).
		2)	U 953 on passage through the Iceland passage encountered in AE 8612 escort groups, bombed by aircraft in AE 8564. No damage.
		3)	U 952 radar location in BD 2221, subsequently hydrophone fix in 117⁰ and distant depth charges.
		4)	U 177 from 13th - 15th May in GR 5656 to 5627. Nothing sighted apart from 2 pilot vessels, with lights. Operations intended during the full moon period in JJ, then later return to Cape Town.
	b)	None.

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	c)	U-boat chase as a result of sightings in DJ 2190 - 2270. (No boat in the vicinity). U-boat sighting in FA 53 - DH 4265, one in the latitude of Biscay, another one at 63⁰ 48' North (U 199?).
	d)	1)	HX 239 see IVb.
		2)	Stragglers from ONS convoy 184 were instructed to make for AK 8878 as rendezvous.
		3)	In an American U-boat situation report, of the 19th May, the enemy presumes 6 U-boats to be in a radius of 200 miles round AK 6750 and 8 boats in the area 47 - 51⁰ N. 30 - 35⁰ W.
		4)	Special intercept message regarding ONS 7 (Convoy No. 40 see IVa).

IV.	Current Operations:
	a)	Supplementary Report on Convoy No. 40. (Group "Danube):
		1)	In a special intercept situation report of the 20th May a Commanding Officer, presumably with ONS 7 convoy, reports details of attack on a U-boat at 0237 on the 17th May, when a vessel was torpedoed. Since no report regarding this was received it must be assumed that the boat in question was lost in the attack. An enquiry from the boats yielded the information that U 636 had heard about 46 depth charges at 0200 on the 17th May in AD 9725.
			It is possible, according to this, that the position of the convoy at 0200 on the 17th May was given above, and it was attacked there. According to dead reckoning, only U 657 can be the one in question. She did not report afterwards in spite of repeated instructions to do so. The assumption that the convoy passed the patrol line in the N, contradicts, however, an earlier special intercept message according to which the position of the convoy at 2300 on the 16th May was supposed to have been in AJ 6663.
		2)	Upon enquiry U 92 further reported that she heard a 0432 on the 17th May from AJ 3679 3 or 4 depth charge detonations in direction 120⁰. This observation seems to indicate a series of depth charges from an aircraft. U 109 could have been in the position given. This boat did not report again later and must be considered lost.
			It can therefore, be assumed that U 657 and 109 probably were no longer operating against Convoy No. 41 but were lost in the course of operations against Convoy No. 40.
	b)	1)	Since previous experience has shown that the enemy always steers a course based on the latest U-boat situation reports Group "Mosel" was, upon receipt of situation report of the 19th May, withdrawn by about 50 miles to the S.W., and subsequently took up position in patrol line from AJ 6495 to AK 7924 at 2000.

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			Towards 1900 a special intercept message was received, in which the following points of rendezvous were ordered for stragglers of HX 239 convoy:
			At 1700 on the 20th May in BC 2682, at 1700 on the 21st May in BD 1148 and at 1700 on the 22nd in AK 8557. It is to be assumed that these positions were also passed by the convoy, and that it was, therefore, proceeding much further S. than the first course instructions indicated.
			In spite of high speed only the most southerly part of the "Mosel" boats could overtake the convoy during the coming night. U 650 - 642 - 603 - 228 - 575 - 621 - 641 - 305 - 569 - 468 - 231 - 218 have, therefore, been ordered to take up patrol line at 0800 on the 22nd May, from AK 7385 to BD 2117. The remaining boats (U 552 - 264 - 378 - 607 - 221 - 666 - 752 - 558 - 336) will operate independently to the E, at highest possible speed, on the presumed course of the convoy.
			The "Danube" boat withdrawing from Convoy No. 41 to the W. will now make for AK 97 and are also to operate against the HX 239 convoy.
		2)	New objective of U 953 and 951 is AK 95.
	c)	U 459 has refueled U 129.
	d)	1)	Loss of U 657 and 109, see IVa.
		2)	U 227 was also operating against Convoy No. 40 but has not reported being up to the convoy. An instruction to report on the weather of the 7th May was not answered with certainty since two boats might have sent the message which was received with signature not decyphered. It is, therefore, possible that U 227 was destroyed while proceeding through the Iceland Passage. In support of this there are several reports of U-boats sightings in AE, the positions in them not being decyphered. Loss of the boat even before operations against the convoys appears to be probable.

V.	Reports of Success:
	U 657 - 1 ship 5,000 GRT.

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- 415 -

22.May 1943.

I.	U 66	-	CC 40	U 202	-	AK 64	U 383	-	BE 69	U 558	-	Op(AJ 69)
	67	-	CE 61	209	-	BF 40	402	-	BE 93	560	-	Op(AK 75)
	91	-	AK 51	211	-	BD 68	403	-	BD 58	575	-	Op(AK 71)
	92	-	AK 61	214	-	BE 95	413	-	AK 59	584	-	BF 48
	103	-	DE 69	217	-	BC 63	418	-	AK 53	603	-	Op(AK 71)
	105	-	ES 88	218	-	Op(AK 79)	435	-	BF 45	607	-	Op(AJ 68)
	107	-	BE 88	221	-	AJ 92	436	-	BD 61	608	-	BE 71
	119	-	Op(CC 23)	223	-	BF 40	448	-	BE 58	614	-	BF 48
	123	-	EJ 76	228	-	AL 71	454	-	BF 91	621	-	Op(AK 74)
	126	-	Op(ET 50)	229	-	BD 56	459	-	BD 91	634	-	BE 69
	128	-	FD 43	230	-	BF 44	460	-	ES 88	636	-	AK 55
	129	-	BD 97	231	-	Op(AK 76)	461	-	BE 45	641	-	Op(AK 75)
	154	-	ES 88	232	-	AK 83	463	-	BE 50	642	-	Op(AK 71)
	161	-	CC 57	258	-	AL 71	466	-	BE 93	645	-	AK 56
	176	-	Op(DN)	260	-	BF 64	467	-	AF 73	650	-	Op(AJ 93)
	177	-	Op(JJ 42)	262	-	BE 91	468	-	Op(AK 75)	664	-	AK 56
	178	-	Op(KZ 40)	264	-	Op(AK 45)	488	-	AF 87	666	-	Op(AJ 68)
	180	-	Op(KY)	266	-	BF 40	504	-	BE 81	667	-	AN 36
	181	-	Op(KP 60)	273	-	AK 51	511	-	EJ 42	707	-	AK 93
	190	-	Op(CC 19)	305	-	Op(AK 75)	513	-	CF 32	709	-	BF 54
	193	-	Bergen	304	-	AK 53	514	-	BF 61	731	-	AK 53
	195	-	Op(KY 88)	336	-	Op(AJ 93)	515	-	ES 88	752	-	Op(AJ 69)
	196	-	Op(KZ 20)	340	-	AK 92	521	-	CD 14	760	-	AK 55
	197	-	GF 39	377	-	BD 55	525	-	BF 44	951	-	AE 82
	198	-	Op(KP 90)	378	-	Op(AJ 68)	527	-	CD 92	952	-	AK 99
	199	-	AE 59	381	-	AK 60	533	-	BE 69	953	-	AE 23
							552	-	Op(AJ 64)	954	-	AK 60

	On Return Passage: U 103 - 107 - 129 - 209 - 223 - 229 - 230 - 260 - 262 - 266 - 340 - 383 - 402 - 436 - 448 - 454 - 461 - 466 - 504 - 515 - 525 - 533 - 584 - 614 - 634 - 707 - 709 - 952.
	Entered Port: U 514 - Lorient; U 260 - St. Nazaire.
	Sailed: U 441 - Brest; U 523 - Lorient.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Reports of Group "Mosel" see IVa.
		2)	U 468 was heavily bombed by aircraft type "Blakburnskua" at 0830 in AK 8794, while surfaced, and at 1600 she was again bombed by "Albakores". Subsequently she was pursued and depth-charged by a sub-chaser group. Return owing to damage.
		3)	U 196 sank on the 11th May in KZ 1383 a freighter of 6,000 GRT. No other traffic observed in the operational area. Slight sea and air patrol.
		4)	U 197 sank Dutch vessel ("Benskat" - 4,763 GRT) course W. on the 20th May in FM 2269. Attack by a "Mitchell", while surfaced, beaten off; in addition 7 aircraft type "Lancaster" observed, with course 30⁰.
	b)	None.

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	c)	None.
	d)	According to a special intercept message the position of OS 47 at 2000 on the 17th May was in DJ 4620, proceeding on course 228⁰, speed 7.3 knots, as from DJ 7110.
		Freetown boats were advised.

IV.	Current Operations:
	a)	1)	During operations against the expected HX 239 (Convoy No. 42) U 305 sighted towards 1300 destroyers in AK 8784. She was, however, detected by a single engined land-based aircraft and bombed. After submerging the boat's hydrophone picked up a broad band with true bearing 110 - 150⁰, but she was unable to pursue owing to damage and withdrew for repair.
			As the convoy must have been in the vicinity, according to dead reckoning, U 569 - 468 - 231 and 218 were sent in following this report. The remaining boats in patrol line proceeded at 9 knots to the E and, in case the convoy was not sighted, were to be disposed in a patrol line. At 1710 U 218 sighted clouds of smoke, mastheads and an aircraft in BD 2129, but lost contact in a rain squall. The report was received towards 2200. The boat suspected course N.E. As it was at first assumed that the convoy via the rendezvous known by special intercept message, 9 boats of Group "Mosel" and 19 boats of Group "Danube" were sent in to operate. They were ordered to operate, the convoy courses being from 50 - 75⁰ degrees and enemy speed 9 knots. The remaining "Mosel" boats (U 650 - 642 - 603 - 228 - 575 - 621 - 641 - 305 - 569 - 468 - 231 and 218) were ordered to remain in the area reached, since pursuit for these boats was hopeless. U 218 was later surprised in BD 2931 by destroyers emerging from the rain squalls and pursued with Asdic and location by explosive soundings. It is possible that these were stragglers which, however, were proceeding further southwards than expected according to special intercept message.
			The boats in operation are now searching, as far as their position allows, more to the E than 75⁰. Up to morning no further reports had been received.
		2)	U 569 was forced continually to submerge in BD 1325 by aircraft and destroyers. She reported, according to hydrophone fix, a southwest-bound convoy in BD 1310. Probably this was ON 184 detected as a result of special intercept message of the 21st May. Operations on this convoy were hopeless in view of the boats being too far behind.
	b)	New objective for U 513 is EH 80. This boat will operate, after refueling from U 460, in the area of the Brazilian coast.
	c)	U 129 took over MG parts from U 608 and is returning.
	d)	1)	U 441 has set out, being the first of the intended Flak boats. For purpose and tasks of these Flak boats, see

- 417 -

			attached Operational Order No. 55.
		2)	U 954 was sent in to operate against Convoy No. 41. She reported this at 1011 on the 19th May in AK 5482, but did not report again in spite of repeated instructions to do so. She must be considered lost. There are no further details (see also 20th May under IVa).
		3)	There has been no report from U 381 since her withdrawal from the tanker on the 10th May. It is not probable that she reached Convoy No. 41 at all. However, it is to be assumed that she fell a victim to the very heavy air reconnaissance in the North Atlantic, especially as several intercept messages have been taken regarding depth charge attacks (see also 20th May under IVa).
		4)	U 273 was probably bombed in AK 3835 on the 19th May. 2 hits were reported by the attacking aircraft. According to reliable dead reckoning, only U 273 could have been near the given position. After the aircraft report had been received the Boat was ordered to give her position, but has not reported. She must be assumed lost.
		5)	U 463 has not reported since sailing from Western France. Since the time for sending her passage report has long elapsed, and since no report has been sent in, in spite of instructions, the boat must be considered lost. There are no further details. Loss through aircraft attack is probable.

V.	Reports of Success:
	U 196 - 1 ship 6,000 GRT
	U 197 - 1 ship 4,763 GRT.

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- 418 -

Naval High Command
Naval War Staff 2/B.d.U. Op.
B. No. Group Command 2564 Al
			7.May 1943.

Most Secret
Operational Order Atlantic No. 55.
for
Flak Boats (U 441 & U 256)

To be used in conjunction with Operational Order Atlantic No. 54.

I.	Operation:
	1)	Attack on enemy aircraft, in particular on incoming and out going routes of the Biscay area up to 15⁰ W.
	2)	Provision of flak escort for U-boats unable to submerge or damaged in other ways.
	3)	Attack on enemy merchant ships and enemy naval units. This is only a subsidiary operation.
	4)	Procedure according to Commanding Officer's Hand Book, Standing War Orders, Permanent Orders and Special Instructions of B.d.U. to be interpreted with regard to the special type of these boats.

II.	Reports on the Enemy:
	See Figure II of Operational Order Atlantic No. 54. Attention is drawn to the following:
	5)	Intensive Air Patrol has been established just lately in the Biscay area, in BF 40 and N. section of BF 70 and 80. Apart from this, continuous air activity eastward of the above squares as well as westward up to about 20⁰ W. Apart from aircraft with radar by day and night, aircraft have also been confirmed just lately without radar being observed at the time. Aircraft operate in attack with searchlights and flares. According to several indications, the use of infra-red or ultra-violet rays appears probable for short-range location.
	6)	Enemy U-boats may be expected in the whole Biscay area, particularly in a line about 100 miles wide off the Spanish north coast. There is no accurate information regarding the area outside this line. The danger of U-boats there, however, is considered to be only slight.

III.	Information regarding our own forces:
	7)	See Operational Order Atlantic No. 54, Fig. III.
		In the whole Biscay area our own U-boats may be expected coming in and out continuously.

- 419 -

IV.	Carrying out Operations:
	8)	Departure according to Departure Order. Make for deep water as soon as possible. No obligation to keep most economical cruising speed. Always proceed at sufficient speed in order to be able to effect quick avoiding action.
	9)	Operational Area: BE 66, 69, 93, BF 44, 45, 46, 47, 48, 49, 71, 72, 73. Further westward at special orders. In the operational area westerly or easterly courses mainly, so that impression is given of a boat departing or returning.
	10)	By day remain surfaced and ward off attacks by aircraft with all means. Guns must be manned continually for action. Aircraft not only to be warded off but shot down. Only submerge in order to rest the crew and in the case of visibility being so bad that the boats might be completely surprised.
	11)	By night remain submerged according to judgment. Consider carefully possibilities of operating surfaced at night. Gain experience.
	12)	a)	Conserve ammunition: Do not use ammunition carelessly when enemy aircraft are out of range. Effective range of 3.7 cm. is 20 - 25 hm., for 2 cm., 10 - 15 hm. If aircraft attacks or flies past within favorable range, fire from all guns. If aircraft flies over the boat fire line-carrying rockets. If the enemy aircraft remains just within range, fire sparingly with 3.7 or from one barrel of the 2 cm. gun.
		b)	For general procedure during an aircraft attack see enclosed instructions which should be followed according to circumstances.
	13)	Operation by boat against convoys only on special instructions by the Control. No underwater attack. Attack against single vessels outside Route A is permitted. Use FAT II in stern tube if necessary as a defense torpedo against destroyers or corvettes (circular run).
	14)	If reports are received from our own boats which have been bombed , are unable to dive or damaged, within reach, proceed at maximum speed without waiting for any special order. Take over flak escort and report action.
	15)	Return Passage:
		a)	After ammunition has been used up, taking into consideration the minimum ammunition supplies necessary for return passage.
		b)	When fuel supplies make it necessary.

V.	Communications:
	16)	Operation Order Atlantic Figure V applies when appropriate.
	17)	Radio wave as a rule is coastal one. Other radio waves as ordered.
	18)	Reports to be made:

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		a)	When requested.
		b)	Position to be reported twice daily by means of a short signal.
		c)	When starting return passage.

VI.	Other matters:
	19)	Trial operations, see Special Order.
	20)	Instructions regarding general procedure when attacked by aircraft, see Enclosure 1.


			For Flag Officer Commanding U-boats
			Chief of Operations
			(Signed): GODT.















- 421 -

Secret

	Enclosure 1 to Operational Orders #55.
	Naval High Command 2 Naval War Staff,
	B.d.U. Op. Order. Group Command 2564.

Instructions regarding Defence against

Enemy Aircraft when surfaced.

Experience has shown that it is better to ward off the attack of aircraft, which have been spotted too late, on the surface that to expose oneself to the danger of accurate bombing by diving without using any defence.

The boat is only safe from bombs from a diving depth of A meters. From the time which is required to attain this depth may be calculated the distance under which it is not permissible to dive from an aircraft. This distance is between 0 and 6,000 m., according to aircraft type and position (flying boat, land-based or carrier-based machine; flight to, from parallel or over).

The Commanding Officer must give his instructions to the Officers of the Watch clearly and repeat them, when boat is not to dive upon aircraft being sighted.

When there is any doubt as to whether to dive or not, it is better to remain surfaced and ward off attacks.

Watches on the bridge should be trained to give full reports (distance near, medium, great; flight to, from or parallel), and the Officers of the Watch to give their orders clearly.

According to our own experiences and statements of prisoners of war, the aircraft attack in a steep glide or dive across the course of the U-boat, and, in order to equalize the small width of the target, release 4 - 6 bombs, generally depth-charges, in a series.

They may be expected to fire with their guns at the same time, particularly when running up to the target.

The defence measures by the boat, i.e. continuous fire from all guns and avoiding action, must be directed to avoiding bomb hits.

Fire is to be opened continuously from all flak guns. If conditions indicate remaining surfaced for a long time the defense guns should also be used, if weather conditions permit. The order to open fire is to be given so that the guns' magazines need not be changed just when firing might be most favorable. According to experiences the inclination is to open fire too soon.

The crew manning the flak guns must be trained by practice to get into the boat for crash-diving in the case of an attack having been warded off, so as not to extend the time required for diving. There will be about 1 1/2 minutes left before another attack.

Avoiding action must be effected at maximum speed and using full helm to the side most unfavorable for the aircraft. It is usually recognized early in the attack whether the aircraft is likely to fly past and the boat can then sheer off. It is nearly always correct, when there is a strong cross-wind, to turn to windward, since the aircraft has difficulties with drift of the wind.

- 422 -

	Orders for turning must not be given too soon, in order not to show the enemy a broad silhouette. They must also not be given too late, as otherwise turning can no longer be effected. According to experience turning is usually made too late.

10)	The code word for beginning defence measures against aircraft is: "Run out M.G."

11)	"Run out M.G." is an action in which all are concerned and must be drilled and trained.

12)	Measures upon "Run out M.G."
	a)	The Officer of the Watch will proceed with both Diesels full speed ahead and keep the aircraft right astern so as to present narrow silhouette and be able to use all the flak guns. If the aircraft is already too near he will immediately open fire and turn to the side which is unfavorable to the aircraft.
	b)	The watch on the bridge will man the flak guns and open fire when ordered.
	c)	The picket watch will supplement the watch on the bridge.
	d)	The rest of the watch will take up position as ammunition men or take up battle stations with the free watch of the technical division, in order to repair any damage or to act as reserves.

13)	After every bombing, the bilges, out-board connections and all important installations should be examined and the result reported to the Commanding Officer by the Chief Engineer.

14)	If it is intended to submerge after the next attack orders should be given to all in good time.

15)	Experiences regarding surface defence against aircraft should be given briefly in the War Diary.


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23.May 1943.

I.	U 66	-	CB 64	U 202	-	Op(AK 91)	U 413	-	Op(AK 81)	U 584	-	BF 40
	67	-	CE 54	209	-	BF 40	418	-	Op(AK 67)	603	-	Op(AK 86)
	91	-	Op(AK 91)	211	-	BD 56	435	-	BE 69	607	-	Op(AK 58)
	92	-	Op(AK 91)	214	-	BE 89	436	-	BD 66	608	-	BE 71
	103	-	BF 48	217	-	BC 64	441	-	BF 46	614	-	BF 58
	105	-	ES 88	218	-	Op(BD 88)	448	-	BE 92	621	-	Op(AK 94)
	107	-	BE 91	221	-	AK 47	454	-	BF 66	634	-	BF 52
	119	-	Op(CC 25)	223	-	BF 58	459	-	BD 59	636	-	Op(AK 91)
	123	-	EJ 45	228	-	Op(AK 83)	460	-	ES 88	641	-	Op(AK 94)
	126	-	Op(ET 60)	229	-	BD 56	461	-	BE 58	642	-	Op(AK 93)
	128	-	ES 88	230	-	BF 54	466	-	BF 48	645	-	Op(AK 91)
	129	-	DD 71	231	-	Op(AK 94)	467	-	AF 67	650	-	Op(AK 83)
	154	-	ES 88	232	-	Op(AK 86)	468	-	Op(BD 25)	664	-	Op(AK 91)
	161	-	CC 64	258	-	AL 84	488	-	AF 76	666	-	Op(AK 83)
	176	-	Op(DN 40)	262	-	BF 71	504	-	BE 83	667	-	AN 28
	177	-	Op(GR 90)	264	-	Op(AK 79)	511	-	EJ 78	707	-	AL 75
	178	-	Op(KY 60)	266	-	BF 40	513	-	CF 61	709	-	BF 52
	180	-	JJ 11	304	-	Op(AK 91)	515	-	ES 88	731	-	Op(AK 91)
	181	-	Op(KP 60)	305	-	Op(BD 21)	521	-	CC 38	752	-	Op(AK 83)
	190	-	Op(CC 41)	336	-	Op(AK 83)	523	-	BF 54	760	-	Op(AK 83)
	193	-	AF 79	340	-	AL 75	525	-	BF 49	951	-	AL 15
	195	-	Op(GR 99)	377	-	BD 56	527	-	CD 86	952	-	BD 64
	196	-	Op(KZ 35)	378	-	Op(AK 83)	533	-	BF 48	953	-	AL 15
	197	-	Op(GG 48)	383	-	BF 48	552	-	Op(AK 83)
	198	-	Op(KY 80)	402	-	BF 72	558	-	Op(AK 83)
	199	-	AL 14	403	-	BD 59	569	-	Op(BD 13)
							575	-	Op(AK 86)

	On Return Passage: U 103 - 107 - 123 - 129 - 161 - 209 - 223 - 229 - 230 - 258 - 262 - 266 - 305 - 340 - 377 - 383 - 402 - 403 - 436 - 448 - 454 - 461 - 466 - 468 - 504 - 525 - 533 - 584 - 614 - 634 - 707 - 709 - 952.
	Entered Port: U 709 - 634 - Brest; U 454 - La Pallice.
	Sailed: U 594 - St. Nazaire.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 42 see IVa.
		2)	U 951 was located and approached by "Lockheed Hudson" while proceeding through the Iceland Passage, in AE 7936, no attack.
		3)	U 91 warded off in AK 9734 2 runs-in by a "Liberator". Subsequently she was located by a chaser group and depth charged. See also IVd.
	b)	None.
	c)	U-boat sightings: DJ 11 (U 447 - 659 ?), AK 9557, DD 15 and a further 5 in unknown position. 1 depth charge attack.
	d)	Special intercept regarding ONS 8 see IVb.

- 424 -

IV.

Current Operations:

Convoy No. 42:

The boats were continually forced to submerge by very strong land-based aircraft, so that approach, apart from attack, was not possible.

U 664, during a shower of rain, came on to the convoy which passed over her in AK 9841. Course was about 70⁰. No contact.

Since the boats were unlikely to achieve any success with the strong air and naval escort, and also damage was continually reported through aircraft bombs, the operation was broken off towards 1100, and the boats were ordered to withdraw to the W. U 413 reported at 1155 the convoy to be in AK 9810 according to hydrophone and aircraft.

The operation has, therefore, been concluded. No successes were achieved. For further details see Final Survey.

Final Survey:

The operation was very much affected at the beginning by the uncertainty of the boats' reports on the 22nd May. The boats were forced continually to remain submerged by numerous carrier-borne aircraft in the area of the patrol from dawn onwards, so that the first report regarding the S.W. bound convoy was not received until 1933 and no report at all was received regarding the expected N.E. bound convoy. It must be assumed that this convoy passed the patrol line in the area of position U 231, and that this boat was attacked and sunk by carrier borne aircraft or escort forces (She has not reported up to now). In this way there was no report on the 22nd May regarding the convoy, and, therefore, no action with any prospect of success in the first night, in view of the escort at the time.

On the 23rd May, the number of various aircraft sightings showed that carrier-borne and land-based aircraft were being used extensively, so that in spite of the knowledge of the convoy's position, the operation had to be broken off.

The following were lost off this convoy:

U 231	on 22nd May	(carrier borne aircraft?)
U 758	on 23rd May	(see War Diary V d 1) of 23rd May)

The following were damaged:

U 468, U 305 by bombing attack of carrier borne aircraft.

Therefore, all losses and damage were caused by enemy aircraft. The operation against the convoy showed again clearly that it is not possible at present to attack, with available weapons, a convoy escorted by strong air cover. The case of U 752, however, proves that the boats will be able to ward off attacks of carrier aircraft after installation of the 2 cm. quadruples.

New temporary objective for U 608 and 211 is AJ 97. U 199 will proceed southward and will be operating in the Cape Town area.

- 425 -

	c)	None.
	d)	1)	U 91 took over survivors from U 752 in AK 9753. They state that the boat was bombed at 1210 on the 23rd May by carrier borne aircraft at periscope depth. She was unable to submerge owing to leakage in the wardroom. She surfaced and warded off 3 further carrier-borne aircraft. When 2 destroyers came into sight the boat was scuttled.
		2)	U 266 has not reported on her arrival, expected for several days. The boat refueled from U 461 on the 12th May in AK 8769 and proceeded on return passage. Apart from several sightings of U-boats by aircraft in BB, BE and BF there are no further details regarding her loss.
		3)	U 209 has been on her return passage since the 6th May. On this day U 954 reported that U 209 was damaged by aircraft bombs and unable to send signals. Fuel supplies which were then 29 cbm must have been used up by now. Although the escort was sent out several times, the boat has not come in up to now, so that she must be considered lost.
		4)	The last report from U 176 was on the 21st May from CD 9574. The boat was ordered to operate in the Florida Straits and, according to several reports of sightings and one of an attack, must have arrived there. The order on the 16th May to report her position was not answered. According to an intercept message, a U-boat in attack was sighted in DM 69. The boat may have been destroyed herself in this attack. She must be considered lost.

V.	Reports of Success: None.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

24.May 1943.

I.	U 66	-	CB 58	U 199	-	AL 17	U 403	-	BD 59	U 558	-	Op(AK 94)
	67	-	CE 72	202	-	Op(AK 89)	413	-	Op(AK 89)	569	-	Op(AK 79)
	91	-	Op(AK 97)	211	-	BD 43	418	-	AK 95	575	-	Op(AK 76)
	192	-	Op(AK 94)	214	-	CF 32	435	-	BE 52	584	-	BF 51
	103	-	BF 49	217	-	BC 67	436	-	BE 45	594	-	BF 58
	105	-	ES 88	218	-	Op(BD 13)	441	-	BF 49	603	-	Op(AK 75)
	107	-	BE 93	221	-	AK 47	448	-	BF 71	607	-	AK 98
	119	-	Op(CC 24)	223	-	BF 64	459	-	BD 59	608	-	BD 59
	123	-	EJ 15	228	-	Op(AK 76)	460	-	ES 88	614	-	BF 64
	126	-	Op(ET 67)	229	-	BD 56	461	-	BE 67	621	-	Op(AK 79)
	128	-	FD 21	230	-	BF 52	466	-	BF 49	636	-	Op(AK 57)
	129	-	BE 81	231	-	Op(AK 87)	467	-	AE 68	641	-	Op(AK 79)
	154	-	ES 88	232	-	Op(AK 97)	468	-	BD 53	642	-	Op(AK 72)
	161	-	CD 41	258	-	BE 15	488	-	AF 48	645	-	Op(AK 86)
	177	-	Op(JJ 42)	262	-	BF 67	504	-	BE 92	650	-	Op(AK 72)
	178	-	Op(KZ 40)	264	-	BD 22	511	-	ES 54	664	-	Op(AK 94)
	180	-	GR 87	304	-	Op(AK 89)	513	-	CF 83	666	-	Op(AK 91)
	181	-	Op(KP 60)	305	-	BD 29	515	-	ES 88	667	-	AF 79
	190	-	CB 61	336	-	Op(AK 91)	521	-	CC 28	707	-	BD 38


- 426 -

193	-	AF 72	340	-	BE 14	523	-	BF 49	731	-	Op(AK 91)
195	-	Op(KY 89)	377	-	BD 56	525	-	BF 40	760	-	AK 95
196	-	Op(KZ 30)	378	-	Op(AK 92)	527	-	CD 79	951	-	AK 39
197	-	GG 84	383	-	BF 51	533	-	BF 61	952	-	BD 93
198	-	Op(KP 90)	402	-	BF 49	552	-	Op(AK 94)	953	-	AL 39

	On Return Passage: U 103 - 107 - 123 - 129 - 161 - 209 - 223 - 229 - 230 - 258 - 262 - 305 - 340 - 377 - 383 - 402 - 403 - 436 - 448 - 461 - 466 - 468 - 504 - 525 - 533 - 584 - 607 - 707 - 760 - 952.
	Entered Port: U 230 - 584 - Brest; U 523 - Lorient; U 614 - 223 - St. Nazaire.
	Sailed: - . -

II.	Air Reconnaissance: West of Portugal.

III.	Reports on the Enemy:
	a)	1)	U 441 (Flak boat) shot down a "Sunderland" in BF 4971, but had to return owing to extensive bomb damage.
		2)	U 523 was also bombed by an aircraft in about BF 40. The boat is able to dive and is returning.
		3)	U 178 sighted about 6 vessels on a north-easterly course in KZ 4110. She warded off an attacking aircraft but was forced to submerge continually owing to strong air cover by day.
	b)	Our own aircraft sighted at 1650 in CG 4945 a convoy consisting of 81 ships. This was probably SL 129 and HX 7, were proceeding together northwards.
	c)	U-boat sightings: CG 8136 and DM 48 (U 176 ?).
	d)	None.

IV.	Current Operations:
	a)	None.
	b)	1)	After breaking off convoy operations the following new disposition is ordered for the boats in the North Atlantic. Reasons for this, see VI. U 569 - 641 - 228 - 603 - 642 - 336 - 558 - 666 - 211 - 608 - 221 - 953 - 951 - 232 - 435 - 217 and 92 will proceed to CD 87. Boats should reach this square by 2000 on the 31st May. Operations are intended against UGS 9, which is expected there about this time.
		2)	In order to give the appearance of strong battle groups the following operational areas are ordered with line of 70 miles covered:
			U 650 = AJ 2938; U 636 = AJ 6285; U 202 = AK 4146; U 575 = AK 4734; U 304 = AK 4675; U 731 = AK 7345; U 378 = AK 6458; U 552 = AK 6883; U 664 = AK 2855; U 413 = AK 3954;U 621 = BD 1252; U 645 = BD 1971; U 91 = AK 8915.

- 427 -

			By means of extensive radio traffic the enemy is to be left in doubt as to the small number of boats in position there.
		3)	U 195 - a IXd1 boat reports that owing to overloading of her engines she will have to proceed back on the 1st June. The boat has been in the operational area off Cape Town for only a few days and has, therefore a comparatively large supply of torpedoes and fuel. As this will be brought back again, operations in such a wide area are not worth while for this type of boat.
	c)	U 403 has refueled from U 459 and is returning.
	d)	U 258 started on return passage from about AK 90 on the 20th May. Since then there has been no further news from the boat. She was probably destroyed on the 20th - 21st May by heavy British air activity.

V.	Reports of Success:
	U 441 - 1 aircraft.

VI.	General:
	In the last few days circumstances have arisen which give a particularly strong indication of the present crisis in U-boat warfare and force us to decisive measures. These circumstances are:
	a)	The further heavy losses which have occurred or been confirmed.
	b)	The failure against convoy SC 130 (Group "Danube") as well as the conditions in operations against HX 239 (Group "Mosel").
	Re a):
	After 14 boats had been lost in the Atlantic in February, in March 13 and in April 12, the extent of the losses in the Atlantic in May has already reached the figure of 31 boats lost up to the 22nd May, and 2 further ones have probably been lost in the operation against HX 239.
	Losses, even heavy losses, must be borne when they are accompanied by corresponding sinkings. But, in May in the Atlantic the sinking of about 10,000 GRT had to be paid for by loss of a boat, while not long ago there was loss only with the sinking of about 100,000 GRT. The losses in May have, therefore, reached an impossible height.
	Investigation regarding the confirmed or probable causes of losses in May give the following result:

- 428 -

Approach			Operational Area			Convoy

Air	Air/Sea	Sea	Air	Air/Sea	Sea	Air	Air/Sea	Sea

465	::	::	109	176	203	753	89	186

332	::	::	192	447	::	456	954	125

439	::	::	227	659	::	640	::	438

663	::	::	::	381	::	::	::	638

528	::	::	::	::	::	::	::	531

463	::	::	::	::	::	::	::	630

266	::	::	::	::	::	::	::	657

646	::	::	::	::	::	::	::	::

273	::	::	::	::	::	::	::	::

182	::	::	::	::	::	::	::	::

258	::	::	::	::	::	::	::	::

11%	::	::	3 B	4 B	1 B	3	2	7

35%	::	::	10%	13%	3%	10%	6%	22%

35%			26%			38%

From the 31 boats lost up to the 22nd May in the Atlantic, therefore, 19, i.e. 60% were lost while proceeding and at waiting positions in the operational area. Only 12 boats, i.e. about 40%, were probably lost while directly attacking the convoy, only 4 - 5 of these in the unusually unfavorable visibility which led to the breaking off of attack on Convoy No. 36.

When the losses are analyzed as to whether caused by aircraft or naval forces, the result is as follows:

20 boats, i.e. 60% were almost certainly destroyed by aircraft, and 6 further ones possibly by aircraft.

Only 8 boats, i.e. 25% were almost certainly destroyed by naval forces.

The Royal Air Force, therefore, played an important part in causing such high losses. This is to be attributed to the increased use of land-based aircraft and aircraft carriers, combined with the possibility of surprise now through the enemy radar location by day and night.

Re b):

The decisive part played by the Royal Air Force has also been confirmed in the attacks on the "Danube" convoy (No. 40) and in operations on HX 239 (No. 42). In the case of the "Danube" convoy aircraft prevented the boats from being able to approach for

- 429 -

attack and only made possible a partial, temporary contact. In the case of Group "Mosel" no real contact was taken up in view of the large number of aircraft which appeared, although presumably one of the two convoys had passed the patrol line.
The excessive losses and the lack of success in operations against the latest convoys now forces us to take decisive measures until the boats are equipped again with better defence and attack weapons.
The first important measure is to prevent losses while proceeding through aircraft. More than ever there arises the old principle "of proceeding carefully like an old bull elephant" and not only on approach and return routes, but also in areas of the North Atlantic which are endangered by aircraft and when in waiting and attack positions. Orders were given on the 22nd for this as follows:

"All Waves" (Message 1752)
All boats.
The danger of being surprised by locating aircraft is very great, especially at night. The following orders are, therefore, given:
1)	Procedure when approaching and returning from the Biscay area and approaching the area home North Atlantic as in Permanent Order No. 13.
2)	Procedure in the operational area North Atlantic when cruising and stopping in position.
	a)	By night: One electric motor slow to half speed, other motor Diesel ready to start up. Boats ventilator switched off. Reason for this: To be able to confirm approaching aircraft by hydrophone. MG ready and manned.
	b)	By day: With higher cruising speed than before confirm that boat can be easily maneuvered and is able to dive.
	c)	If weather conditions are unfavorable by day and night proceed only underwater.
3)	When contacting the enemy: Operations as before.

"To All Boats" (Message 1769).
In almost every operation boats are seriously endangered by submerging in view of aircraft even when a safe depth cannot be reached before the bombs are released. It should be impressed on all Officers of the Watch that when the protective depth i.e. 80 to 100 m., can no longer be attained with certainty before bombs are released, i.e. always when the watch on the bridge is taken by surprise, it is best to remain surfaced and ward off the aircraft attack with Flak guns. We do not know how often loss has been caused by submerging too late. However, we do know that defense measures when surfaced have led to success in all cases reported.


- 430 -

	Apart from this, the situation in the North Atlantic now forces a temporary shifting of operations to areas less endangered by aircraft. The following areas come into consideration: the Caribbean Sea, the area off Trinidad, the area off the Brazilian and West African coasts. It is, therefore, intended to operate primarily with VIIC boats in these areas, as far as permitted by the supply situation. If necessary, operational boats must also be sent in to supply other boats. With the boats at present in the North Atlantic, operations will be made against the traffic between USA and Gibraltar - as far as these boats are able to do this with their fuel. The North Atlantic cannot, however, be entirely denuded of boats. It is necessary, by means of single boats, to leave the enemy in ignorance as long as possible regarding alterations in tactics. For this operation in the North Atlantic boats are available now which cannot be sent elsewhere in view of their fuel supplies, and also boats coming from home waters for their first operations, which must be assigned the stay in the North Atlantic in spite of the difficult conditions. It is intended to attempt attacks on a convoy only under particularly favorable conditions, i.e. in the time of the new moon. The new moon period at the end of June is the first to come into consideration, since the boats at present in the North Atlantic are no longer operational enough. It will be necessary to assign several veteran boats for this as a support for the newer boats in the North Atlantic.
	These decisions comprise a temporary deviation from the former principles for the conduct of U-boat warfare. This is necessary in order not to allow the U-boats to be beaten at a time when their weapons are inferior, by unnecessary losses while achieving very slight success. It is, however, clearly understood that the main operational area of U-boats is, as it always was, in the North Atlantic and that operations must be resumed there with every determination as soon as the U-boats are given the necessary weapons for this. Equipment with 2 cm., quadruples, which will begin as from June to an increasing degree will be the first step in this direction, equipment with Zaunkönig torpedoes (anti-destroyer) the second step, while improvement of location devices at the moment is still to be considered. It is, however, anticipated that after equipment with quadruples, i.e. from the Autumn, the battle of the North Atlantis will be completely resumed once more.
	In the meantime it is essential that the morale of the men should not be affected by these temporary defensive measures, a task which requires full cooperation of the Commanding Officers, as well as the personal touch of the Commander in Chief of the Navy.

			(Signed): DÖNITZ.

- 431 -

		Enclosure 1 to War Diary of 24th May.

"To all U-boat Commanders"
1)	Our heavy U-boat losses in the last month are to be attributed primarily to the present superiority of enemy location gear and the surprise attacks from the air enabled by these. More than half of these losses have occurred by reason of their surprise tactics, on approach and return passage, as well as in the operational area in attack positions. The losses in attacks against convoys themselves were, however, slight except for one case in which conditions were particularly unfavorable. A part of these losses also occurred through air attack.
2)	The present situation in regard to enemy aircraft and enemy location must be counterbalanced, through entailing other disadvantages, by special precautionary measures while proceeding and in waiting positions. Orders regarding this have been issued. I shall also come to further conclusions in the selection of operational area.
3)	I am directing my whole attention to the improvement of our own location, anti-location means and Flak armament. This problem is being worked on everywhere with great concentration. Practical results will shortly be introduced for operations. Until then cruising and waiting must be carried out with skill and care, but actual attacks with the same tenacity as ever.

		"Naval Commander in Chief and Flag Officer
		Commanding U-boats"








- 432 -

Most Secret

24.May 1943.

Order of the Day

To all U-boat Officers.

The increasingly hard and bitter struggle against our victory leads me to emphasize to you the seriousness of our present situation and future. You know that we are fighting off successfully with the army and air force on all fronts the extremely strong attacks of the enemy, engagements being very heavy in some cases. This battle for the security of the homeland and occupied territories must be carried in in order to ensure food for our people and the manufacture of weapons and ammunition for the front. You must understand clearly that the present struggle only constitutes a stand against an enemy stronger in men and material but it does not suffice to bring about a speedy and definite victory.

You alone can, at the moment, make an offensive attack against the enemy and beat him. The U-boat must, by continuous sinking of ships with war material and the necessary supplies for the British Isles, force the enemy to continual losses which must slowly but steadily sap the strength of the strongest force. The German people have long felt that our boats constitute the keenest and most decisive weapon and that the outcome of the war depends on the success or failure of the Battle of the Atlantic.

Each one of you must be aware of his great responsibility and every Commanding Officer must be able to say that he has conducted operations with every effort and tenacity in order to attain our important goal. I know that operations for you out there at the moment are some of the hardest and most costly in losses, since the enemy's defence at the moment is superior in view of new technical methods. Believe me, I have done everything and will continue to do so, in order to introduce means to counter this enemy advance. The time will soon come in which you will be superior to the enemy with new and stronger weapons and will be able to triumph over your worst enemies, the aircraft and the destroyer.

In the meantime we must master the situation with the measures already ordered and with a partial change in operational areas. We will, therefore, not allow ourselves to be forced into the defensive and will not rest but, where there is an opportunity, continue to strike and fight on with still more fortitude and decision in order to make ourselves even stronger for the decisive Battle of the North Atlantic, which will be carried out shortly with improved weapons, in the area most vulnerable for the enemy.

We will then be the victors, - my faith in our boats and in you convinces me of this.

Heil Hitler,

Commander in Chief

Dönitz.

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25.May 1943.

I.	U 66	-	CB 49	U 198	-	Op(KP 90)	U 413	-	AK 91	U 558	-	BD 25
	67	-	CD 95	199	-	AL 44	418	-	AK 95	569	-	BD 18
	91	-	Op(BD 89)	202	-	AK 85	435	-	BE 46	575	-	Op(AK 47)
	92	-	BD 34	211	-	BD 49	436	-	BE 55	594	-	BF 49
	103	-	BF 55	214	-	CF 61	441	-	BF 55	603	-	BD 14
	105	-	ES 88	217	-	BC 98	448	-	BF 48	607	-	BD 33
	107	-	BF 55	218	-	BD 64	459	-	BD 65	608	-	BD 85
	119	-	Op(CC 24)	221	-	AK 77	460	-	ES 88	621	-	Op(BD 12)
	123	-	DT 75	228	-	BD 14	461	-	BE 68	636	-	AK 48
	126	-	Op(ET 60)	229	-	BD 56	466	-	BF 91	641	-	BD 17
	128	-	ES 88	231	-	AK 87	467	-	AE 67	642	-	BD 11
	129	-	BE 83	232	-	BD 25	468	-	BD 65	645	-	Op(BD 99)
	154	-	ES 88	262	-	BF 64	488	-	AE 66	650	-	AK 47
	161	-	CD 19	264	-	BD 37	504	-	BF 92	664	-	AK 67
	177	-	Op(JJ 40)	304	-	AK 82	511	-	ES 88	666	-	AK 87
	178	-	Op(KZ 18)	305	-	BE 62	513	-	CF 88	667	-	AF 76
	180	-	GR 74	336	-	BD 22	515	-	ES 88	707	-	BE 44
	181	-	Op(KP 60)	340	-	BE 16	521	-	CC 43	731	-	AK 82
	190	-	CB 55	377	-	BD 55	523	-	BF 47	760	-	BE 33
	193	-	AF 47	378	-	AK 96	525	-	BF 55	951	-	AK 67
	195	-	Op(JJ 50)	383	-	BF 28	527	-	DE 33	952	-	BE 75
	196	-	Op(KZ 30)	402	-	BF 91	552	-	Op(AK 68)	953	-	AK 59
	197	-	GQ 12	403	-	BD 68

	On Return Passage: U 103 - 107 - 129 - 161 - 218 - 229 - 258 - 262 - 305 - 340 - 377 - 383 - 402 - 403 - 436 - 448 - 461 - 466 - 468 - 504 - 525 - 607 - 707 - 760.
	Entered Port: U 383 - Brest; U 262 - St. Nazaire.
	Sailed: U 118 - Bordeaux; U 535 - 450 - 341 - Kiel.

II.	Air Reconnaissance: In area CG for north-bound convoy.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 43 see IVa.
		2)	According to a report by U 305, U 231 was bombed on the 12th May by carrier-borne aircraft at 9 m., and heavily damaged. Main and long wave senders out of action. Returning.
		3)	U 196 was located in KZ 1368, while attacking the convoy reported by U 178 on the 24th May, and depth-charged by a destroyer.
	b)	Aircraft attacked the expected convoy in CG. No observations on the results. It is not intended to operate with U-boats.
	c)	U-boat sightings: BD 2571 - AE 8695 - CH 7667 - AE 8630 and a further one in position not decyphered.
	d)	Special intercept messages:
		1)	American U-boat in patrol position AJ 53.
		2)	Troop transport "Westpoint" will proceed on about on about the 26th May over CC 7664 and CB 5885.

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		3)	HX 240 - position at 1500 on the 25th May was BC 8469. No course given.

IV.	Current Operations:
	a)	Convoy No. 43:
		While proceeding to her new disposition U 558 sighted at 1715 in BD 2151 the SC 131 convoy, with course 50⁰, calculated by dead reckoning to be approximately in this position. A large operation was not intended, since the majority of the boats available were not able to carry out the planned attack against the America-Gibraltar convoy in view of fuel shortage, and also they would not have arrived in time.
		U 558 was given freedom of action. Boats in an advanced position, which would be able to come up to attack in the night, were also ordered to operate against the convoy, but to break off operations if enemy aircraft appeared.
		The boats at present in AK 60, U 413 - 664 and 552, were also sent in to operate. These were to proceed so that the convoy was reached before dark on the 26th May. U 558 maintained continuous contact and reported the convoy, consisting of 16-20 vessels, at 2146 in AK 8979. The speed by dead reckoning was about 8-9 knots, course 50-60⁰. Out of the boats operating U 91 submerged for a short time in AK 8982 in view of an aircraft and subsequently requested beacon signals. U 951 also reported operating against the convoy. During a daylight attack U 558 was detected by escorts, depth-charged and, while pressing on, was forced to submerge once more by aircraft and a destroyer. She withdrew owing to damage. Contact, therefore, was lost and not taken up again by next morning. The operation is going on.
	b)	The following operational areas are ordered for boats proceeding to America:
			U 190 will take up the area N. of Cape Hatteras,
			U 66 that S. of Cape Hatteras,
			U 521 has freedom of action in the whole area.
		There is no information at present regarding the traffic situation, but a large number of land-based aircraft may be expected by day and night.
	c) -	d)	None.

V.	Reports of Success: None.

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26.May 1943.

I.	U 66	-	CA 93	U 197	-	GQ 27	U 413	-	Op(AK 92)	U 552	-	Op(AK 86
	67	-	CD 88	198	-	Op(KP 90)	418	-	AL 78	558	-	BD 22
	91	-	Op(AK 89)	199	-	AK 67	435	-	BE 71	569	-	BD 48
	92	-	BD 56	202	-	Op(AK 49)	436	-	BE 64	575	-	Op(AK 47)
	103	-	BF 61	211	-	BD 78	441	-	BF	594	-	BF 48
	105	-	BF 92	214	-	CF 30	448	-	BF 49	603	-	BC 62
	107	-	BF 61	217	-	BC 88	450	-	AO	607	-	BE 18
	118	-	BF 92	218	-	BD 65	459	-	BD 65	608	-	CE 12
	119	-	Op(CC 15)	221	-	BC 39	460	-	ES 88	621	-	Op(BD 12)
	123	-	DT 45	228	-	BD 44	461	-	BF 45	636	-	Op(AJ 63)
	126	-	Op(ET 60)	229	-	BD 56	466	-	BF 68	641	-	BD 44
	128	-	ES 88	231	-	AK 80	467	-	AE 82	642	-	BD 42
	129	-	BE 92	232	-	BD 54	468	-	BE 45	645	-	Op(BD 19)
	154	-	ES 88	264	-	BD 63	488	-	AE 68	650	-	Op(AJ 62)
	161	-	CD 25	304	-	Op(AK 46)	504	-	BF 83	664	-	Op(AK 92)
	177	-	Op(JJ 40)	305	-	BD 65	511	-	ES 88	666	-	BD 18
	178	-	Op(KZ 10)	336	-	BD 27	513	-	DH 18	667	-	AF 72
	180	-	GQ 68	340	-	BE 28	515	-	ES 88	707	-	BE 73
	181	-	Op(KP 60)	341	-	AO	521	-	CB 66	731	-	Op(AK 73)
	190	-	CB 49	377	-	BD 56	523	-	BF 46	760	-	BE 15
	193	-	AE 68	378	-	BE 11	525	-	BF 61	951	-	AK 97
	195	-	Op(JJ 20)	402	-	BF 68	527	-	BE 26	952	-	BE 76
	196	-	Op(KZ 20)	403	-	BE 47	535	-	AO	953	-	BD 21

	On Return Passage: U 103 - 107 - 129 - 161 - 218 - 229 - 258 - 305 - 340 - 377 - 402 - 403 - 436 - 448 - 461 - 466 - 468 - 504 - 525 - 607 - 707 - 760 - 952.
	Entered Port: U 441 - Brest; U 448 - St. Nazaire; U 523 - 525 - 103 - 107 - Lorient; U 402 - 466 - La Pallice.
	Sailed: U 409 - Brest; U 440 - St. Nazaire; U 758 - Bordeaux.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	Convoy No. 43 see IVa.
		2)	U 413 warded off the attack of a "Lancaster" at dawn. The aircraft subsequently circled at 4,000 meters. Boat submerged in a favorable position.
	b)	None.
	c)	U-boat sightings: CH 8386 - CG 1189 - AK 9482 - AK 95 - BD 2321 and 2 in an unknown position.
	d)	None.

IV.	Current Operations:
	a)	Convoy No. 43:
		Contact was not taken up again. Boats broke off operations one after the other owing to strong and continuous air cover, and returned to their operational area or to new positions.

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		U 558 has repaired damage and is, therefore, again ready for operations.
		The operation is concluded. No success was achieved. No losses on our part.
	b)	The south-bound boats will be disposed as intended to intercept a convoy bound from America to Gibraltar.
		U 92 - 558 - 953 - 951 - 435 - 666 - 336 - 232 - 642 - 221 - 603 - 228 - 641 - 569 - 608 - 211 - 217 have been ordered to take up patrol line from CD 4657 to DF 4221 at 0800 on the 1st June as Group "Trutz".
	c)	U 218 gave reserve fuel over to U 459. The latter supplied U 92 for further operations.
	d)	None.

V.	Reports of Success: None.

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27.May 1943.

I.	U 66	-	Op(DC)	U 198	-	Op(KP 90)	U 413	-	AK 67	U 575	-	Op(AK 47)
	67	-	DF 12	199	-	AK 89	418	-	BE 15	594	-	BF 74
	91	-	Op(AK 89)	202	-	Op(AK 41)	435	-	CE 23	603	-	CD 95
	92	-	BD 65	211	-	CD 35	436	-	BE 68	607	-	BE 51
	105	-	ES 88	214	-	BE 76	440	-	BF 57	608	-	CD 39
	118	-	BF 85	217	-	CD 19	450	-	AN 35	621	-	BD 28
	119	-	Op(BB 80)	218	-	BD 65	459	-	BD 65	636	-	Op(AJ 63)
	123	-	DT 15	221	-	BC 69	460	-	ES 88	641	-	BC 96
	126	-	Op(ET 80)	228	-	BC 96	461	-	BF 70	642	-	BD 71
	128	-	ES 88	229	-	BD 56	467	-	AE 84	645	-	Op(BD 19)
	129	-	BE 93	231	-	BE 45	468	-	BE 57	650	-	AK 47
	154	-	ES 88	232	-	BD 75	488	-	AE 83	664	-	Op(AK 53)
	161	-	CD 32	264	-	BE 45	504	-	BF 92	666	-	AK 89
	177	-	Op(JJ 40)	304	-	Op(AK 46)	511	-	ES 88	667	-	AF 76
	178	-	Op(KZ 30)	305	-	BE 46	513	-	DG 66	707	-	BE 94
	180	-	GQ 53	336	-	BD 48	515	-	ES 88	731	-	AK 82
	181	-	Op(KP 60)	340	-	BE 61	521	-	CB 56	758	-	BF 93
	190	-	Op(CA)	341	-	AN 30	527	-	DE 51	760	-	BD 33
	193	-	AE 67	377	-	BD 56	535	-	AN 30	951	-	AK 67
	195	-	Op(JJ 20)	378	-	BE 16	552	-	BE 11	952	-	BE 88
	196	-	Op(KZ 24)	403	-	BE 49	558	-	BD 51	953	-	AK 59
	197	-	CG 64	409	-	BF 54	569	-	BC 99

	On Return Passage: U 123 - 129 - 161 - 180 - 218 - 229 - 231 - 264 - 305 - 340 - 377 - 378 - 403 - 413 - 418 - 436 - 459 - 461 - 468 - 552 - 607 - 621 - 707 - 760 - 952.
	Entered Port: - . -
	Sailed: U 170 - 669 - Kiel.

II.	Air Reconnaissance: None.

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III.	Reports on the Enemy:
	a)	U 181 pursued the Swedish vessel "Sicilia" from KP 53 to KP 3578 and sank her, after the crew had left the ship. The boat had been 10 days in KP 53 and 5 days in KP 35 and sighted nothing except 11 neutral vessels. She suspected camouflaged enemy vessels in view of inaccurate markings.
	b)	None.
	c)	U-boat sightings: AN 3274, AK 9572, BE 6583.
	d)	1)	An American U-boat was in AK 5445 at 2100 on the 24th May en route for patrol area in AK 7657. A further boat was in area AK 7182.
		2)	Convoy of 12 landing craft was in DF 6610 at 2000 on the 26th May, eastward-bound.
			A further 19 landing craft left Norfolk for Gibraltar on about the 24th May.

IV.	Current Operations:
	a)	None.
	b)	Boats en route for the Caribbean will be informed regarding the traffic situation in that area.
	c)	1)	U 460 refueled U 154 - 105 - 505 and 511 for further operations. U 128 has not arrived up to now.
		2)	U 377 refueled from U 229 for return passage.

V.	Reports of Success:
	U 181 - 1 ship 1,633 GRT.

VI.	General:
	The following experiences from recent operations against convoys will be sent by radio to the boats as "Permanent Order No. 42":
	a)	Only a plot drawn up accurately with every report on the enemy and the enemy route marked in enables one to find a convoy quickly and operate successfully against it.
	b)	The first night of operations always promises the best chance of success. Therefore, try to fire as quickly as possible when the convoy is reached.
	c)	On moonlight nights the enemy appears to protect primarily the side away from the moon. Attacks from the moon side, therefore, are more likely to be successful in many cases, also in view of less danger of location.
	d)	Always try to escape on the surface from locating escort vessels, since the enemy usually breaks off the chase quickly and cannot leave the convoy for too long.

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	e)	Try to ward off escort aircraft if possible at once, if Flak guns are ready for action, but above all before dark in order not to lose valuable chances of attack.
	f)	Only submerge in view of aircraft if the boat can with certainty reach at least 80-100 m. If there is any doubt remain surfaced and ward off attack. Train the crew for this and keep in mind the danger of being bombed at low diving depth.
	g)	Make every effort to eliminate the possibilities of surprise attacks while underway and in position. Either proceed with main engine running, in order to hear aircraft beforehand, or submerge in unfavorable weather conditions.
	h)	In some cases decoy depth charges were again dropped with great success.Do not be deceived by these but go to periscope depth as quickly as possible, if there are no hydrophone fixes, and investigate.
	j)	If the convoy wave length is very busy use alternative wave lengths.

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28.May 1943.

I.	U 66	-	Op(DC)	U 198	-	Op(KP 90)	U 418	-	BE 51	U 594	-	BE 65
	67	-	DE 36	199	-	BD 28	435	-	CE 19	603	-	CD 25
	91	-	Op(AK 89)	202	-	Op(AK 41)	436	-	BF 47	608	-	CD 64
	92	-	BD 85	211	-	CD 64	440	-	BF 82	621	-	BD 36
	105	-	ET 72	214	-	CF 13	450	-	AN 29	636	-	Op(AJ 62)
	118	-	BF 76	217	-	CD 49	459	-	BE 48	641	-	CD 29
	119	-	BB 70	218	-	BE 45	460	-	ES 88	642	-	CD 34
	123	-	DG 95	221	-	CD 23	461	-	BF 80	645	-	Op(BD 19)
	126	-	Op(ET 60)	228	-	CD 25	467	-	AE 79	650	-	Op(AJ 29)
	128	-	ES 88	229	-	BD 56	468	-	BF 58	664	-	Op(AK 28)
	129	-	BF 72	231	-	BE 57	488	-	AE 85	666	-	CD 31
	154	-	FC 63	232	-	CD 37	504	-	ES 88	667	-	AE 68
	161	-	BD 87	264	-	BE 57	511	-	FD 37	669	-	AO 40
	170	-	AO 40	304	-	Op(AK 46)	513	-	DG 92	707	-	BE 89
	177	-	Op(JJ 40)	305	-	BE 58	515	-	ES 98	731	-	Op(AK 73)
	178	-	Op(KZ 10)	336	-	CD 32	521	-	CB 57	758	-	BF 86
	180	-	GQ 24	340	-	BE 65	527	-	DE 48	760	-	BE 53
	181	-	Op(KP 60)	341	-	AN 28	535	-	AN 29	951	-	BD 72
	190	-	Op(CA)	377	-	BD 56	552	-	BE 15	952	-	BE 89
	193	-	AE 83	378	-	BE 51	558	-	BD 75	953	-	BD 72
	195	-	Op(JJ 20)	403	-	BE 58	569	-	CD 29	607	-	BE 53
	196	-	Op(KZ 20)	409	-	BF 48	575	-	Op(AK 47)
	197	-	GQ 93	413	-	AK 03

	On Return Passage: U 123 - 129 - 161 - 180 - 218 - 229 - 231 - 264 - 305 - 340 - 377 - 378 - 403 - 413 - 418 - 436 - 459 - 461 - 468 - 552 - 607 - 621 - 707 - 760 - 952.
	Entered Port: U 504 - Bordeaux.
	Sailed: - . -

II.	Air Reconnaissance: None.

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III.	Reports on the Enemy:
	a)	1)	U 594 reported: at 2200 on the 27th May in BE 6558 and at 1530 on the 28th May in 6467 attacks by a "Lancaster" warded off in each case, several hits being made. Bombs fell short or were jettisoned.
		2)	U 511 transmitted the proposal by Admiral Nomura regarding the handing over of a Metox device to Japanese Atlantic boat.
	b)	None.
	c)	U-boat sightings: CG 81, BF 42, CA 98, four further reports, position not clear, from the Iceland area.
	d)	None.

IV.	Current Operations:
	a)	None.
	b)	U 488 instructed to proceed to CB 47. (Square for refueling Group "Trutz").
	c) -	d)	None.

V.	Reports of Success: None.

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29.May 1943.

I.	U 66	-	Op(DC 10)	U 197	-	GR 75	U 409	-	BE 69	U 575	-	Op(AK 47)
	67	-	DE 37	198	-	Op(JA 16)	413	-	AK 44	594	-	BE 83
	91	-	Op(AK 89)	199	-	BD 55	418	-	BE 53	603	-	CD 54
	92	-	CD 33	202	-	Op(AK 41)	435	-	CD 63	607	-	BE 65
	105	-	ET 81	211	-	CD 82	436	-	BF 40	608	-	CD 82
	118	-	BF 74	214	-	CF 42	440	-	BF 73	621	-	BE 18
	119	-	BB 70	217	-	CD 78	450	-	AN 24	636	-	Op(AJ 62)
	223	-	DG 69	218	-	BE 54	459	-	BE 57	641	-	CD 58
	126	-	Op(ET 60)	221	-	CD 52	460	-	ES 88	642	-	CD 55
	128	-	ES 88	228	-	CD 54	461	-	BF 80	645	-	Op(BD 19)
	129	-	BF 61	229	-	BD 86	467	-	AL 21	650	-	Op(AJ 29)
	154	-	FC 67	231	-	BE 59	468	-	BF 68	664	-	AK 53
	161	-	BD 86	232	-	CD 56	488	-	AL 14	666	-	CD 29
	170	-	AN 35	264	-	BE 59	511	-	FD 82	667	-	AE 59
	177	-	Op(GR 42)	304	-	Op(AK 46)	513	-	DT 16	669	-	AN 35
	178	-	Op(KZ 10)	305	-	BE 59	515	-	ET 78	707	-	BE 95
	180	-	GG 94	336	-	CD 29	521	-	CB 71	731	-	Op(AK 73)
	181	-	Op(KP 60)	340	-	BF 44	527	-	DD 69	758	-	BF 84
	190	-	Op(CA 80)	341	-	AF 87	535	-	AF 87	760	-	BE 65
	193	-	AE 84	377	-	BE 44	552	-	BE 19	951	-	CD 31
	195	-	Op(JJ 20)	378	-	BE 53	558	-	CD 23	952	-	BE 95
	196	-	Op(KZ 20)	403	-	BE 67	569	-	CD 58	953	-	CD 31


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	On Return Passage: U 123 - 129 - 161 - 180 - 218 - 229 - 231 - 264 - 305 - 340 - 377 - 378 - 403 - 413 - 418 - 436 - 459 - 461 - 468 - 552 - 607 - 621 - 707 - 760.
	Entered Port: U 129 - Lorient; U 468 - La Pallice.
	Sailed: U 563 - Brest; U 508 - 530 - 172 - Lorient; U 592 - St. Nazaire; U 271 - 308 - Kiel.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	U 154 reported: on the 28th May convoy in EB 9621, course W. 3 ships, together 21,500 GRT sunk, 1 tanker 6,000 GRT probably sunk and a tanker 8,000 GRT torpedoed. During the attack there was some noisy radar location by destroyers up to 2,000 m., but without boat being detected. Subsequently continuous air activity by day. Boat withdrew temporarily to the N. owing to engine repairs and for reloading.
		2)	U 409 reported at 1200 a vessel in CG 1356, 225⁰. Contact lost because of Spanish vessel "Iciar".
		3)	U 552 reported at 0200 in BE 2858 heavy aircraft bombs; able to submerge easily up to 30 m. but all flak guns out of action.
		4)	U 177 sighted in GR 6769 a convoy consisting of 9 vessels, course 125, speed 10 knots. Escort forces being inexperienced, the boat sank 1 tanker and 2 freighters, together 24,000 GRT. Further operations intended in GR 53.
	b)	None.
	c)	U-boat sightings: DN 75, BE 65, a further one sighted, on position given, in area BE and AE (in the latter case attack with depth charges).
	d)	None.

IV.	Current Operations:
	a)	None.
	b)	1)	The following have been ordered into new operational areas: U 527 off Yucatan and Florida Straits, main area of operation being DM 10 and 40 - 50 N. sector; U 67 - area off Windward Passage, Bahama Channel and Jamaica, main areas of operations being DN 70, 80, EC 10.
		2)	Orders for Group "Trutz": operations intended against W. to E. convoy, expected in patrol line as from the 1st June. Speed 8 to 8.5 knots. From 1st to 6th June there is expected, in approximately the area of Struckmeir's position, an E-bound convoy consisting of assault landing craft of 250 GRT and their tankers escorted by patrols. There is to be no operation against these. Favorable opportunities for firing on important targets (tankers) to be utilized. No report on sighting of this convoy.

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On the prescribed route for neutrals heavy traffic at the present. Report will be sent out daily. Do not reveal presence. Only use radio if spotted by the enemy.

Inform the other boats in the North Atlantic: Stragglers of an E-bound convoy proceeding on route over following positions: AJ 9355, AK 1895.

None.

In order to make it difficult for enemy aircraft in the Biscay area to find U-boats and in order, in case of enemy air attacks, to be able to counter the enemy when surfaced, which has proved to be most practical , with heavy and successful gunfire, all boats returning in a position W. of 16⁰ should continue the return passage together, through the Biscay area in Groups up to 4 boats.

The following will rendezvous:

1) on 31st May in BE 4655, U 552 and 377.

2) on 1st June U 644 - 413 - 91 in BE 4115.

3) U 229 and 161 will return together after refueling.

U 707 which is able to submerge and is proceeding with U 952 will be closely escorted on the 30th May by 5 Ju. 88 until met by escorts.

Since U 128 did not arrive for refueling she must be considered lost. The last report on the 17th May was from FJ 6755. There is an action report for the same day from FJ 68 (see War Diary of 17th May).

Reports of Success:

U 154	3 ships	21,500
	2 ships	14,000	torpedoed
U 177	3 ships	24,000

VI.

General:

The measure taken according to IV d) 1) of today for boats on return passage will be introduced by way of experiment for outgoing boats, this being passage together through the Biscay area in groups of between 3 and 6 boats. The F.d.U. will see that these measures are carried out and has received the following instructions in this connection:

The Naval Commander in Chief has ordered the experimental introduction for outgoing boats, at the earliest possible moment, of the method of proceeding together in daylight and on surface in order to ward off enemy aircraft attacks.

Points to be remembered:

Minimum number of boats 3, maximum number 6.

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		b)	Rendezvous for boats coming from different harbors at dawn outside the approach routes. Change points of rendezvous.
		c)	Proceed together, surfaced, by day under the orders of the most senior Commanding Officer. Strict orders not to submerge in case of an aircraft attack but to ward off attack with all guns.
		d)	Proceed submerged at night with prescribed speeds and rendezvous for next morning.
		e)	If it is not possible to use guns disperse or proceed submerged according to the order of the most senior Commanding Officer.
		f)	Escort by aircraft, as far as possible, especially at the point of rendezvous.
		g)	Disperse at about 15⁰ W.
	3)	Authorizing instructions will be issued by the Captain, U-boats West with a report at the same time to Flag Officer Commanding U-boat Operations.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

30.May 1943.

I.	U 66	-	Op(DC 20)	U 199	-	BD 85	U 413	-	AK 67	U 575	-	Op(AK 47)
	67	-	DE 55	202	-	Op(AK 41)	418	-	BE 64	592	-	BF 58
	91	-	BD 34	211	-	DF 16	435	-	CD 64	594	-	BE 89
	92	-	CD 34	214	-	CF 49	436	-	BF 40	603	-	CD 84
	105	-	ET 91	217	-	DF 18	440	-	BF 70	607	-	BF 66
	118	-	BE 90	218	-	BE 59	450	-	Bergen	608	-	DF 21
	119	-	BB 70	221	-	CD 58	459	-	BE 83	621	-	BE 29
	123	-	DG 39	228	-	CD 81	460	-	ES 81	636	-	Op(AJ 62)
	126	-	Op(ET 60)	229	-	BD 86	461	-	BF 93	641	-	CD 84
	154	-	Op(FC 68)	231	-	BF 91	467	-	AL 10	642	-	CD 57
	161	-	BD 86	232	-	CD 82	488	-	AL 17	645	-	Op(BD 18)
	170	-	AN 31	264	-	BE 67	508	-	BF 54	650	-	Op(AJ 29)
	172	-	BF 54	271	-	AO 40	511	-	FD 99	664	-	AK 67
	177	-	Op(JJ 40)	304	-	Op(AK 46)	513	-	DT 41	666	-	CD 58
	178	-	Op(KZ 10)	305	-	BE 68	515	-	ET 88	667	-	AE 85
	180	-	GG 82	308	-	AO 40	521	-	Op(CA-DC)	669	-	AN 31
	181	-	Op(KP 65)	336	-	CD 55	527	-	DD 94	707	-	BF 86
	190	-	Op(CA 80)	340	-	BF 40	530	-	BF 54	731	-	Op(AK 73)
	193	-	AE 79	341	-	AF 76	535	-	AF 76	758	-	BF 70
	195	-	Op(JJ 20)	377	-	BE 71	552	-	BE 51	760	-	BF 91
	196	-	Op(KZ 20)	378	-	BE 64	558	-	CD 28	951	-	CD 53
	197	-	FV 85	403	-	BE 68	563	-	BF 54	952	-	BF 86
	198	-	Op(JA 10)	409	-	CG 16	569	-	CD 87	953	-	CD 29

	On Return Passage: U 123 - 161 - 180 - 218 - 229 - 231 - 264 - 305 - 340 - 377 - 378 - 403 - 413 - 418 - 436 - 459 - 461 - 552 - 607 - 621 - 664 - 760.
	Entered Port: U 461 - Bordeaux.
	Sailed: U 455 - St. Nazaire.

- 443 -

II.	Air Reconnaissance: Against convoy traffic in area CG.

III.	Reports on the Enemy:
	a)	1)	U 731 was surprised during chase of a heavily escorted single vessel by a destroyer and forced to submerge. Contact lost.
		2)	U 126 sank in ET 6243 a large three-masted vessel, Type C 3, escorted by destroyers, with one torpedo. Depth set 7m.
		3)	U 511 sighted on the 29th May in FD 9571 two destroyers, three steamers and 2 further clouds of smoke, course 90⁰, speed 12 knots. Escort by ship's aircraft.
		4)	U 196 situation: Aircraft by day and patrols in KP 8780. In KZ 2150 in dark night approach by aircraft twice without previous location. Flares near the boat. By day unusually good possibilities of out-maneuvering aircraft unseen when surfaced.
		5)	U 178 reported a convoy at 0700 in KY 6280, course E.
	b)	Our own aircraft: sighted at 1220 a convoy consisting of 10 merchant vessels and an escort in CG 8266, course 0⁰.
	c)	1)	U-boat sightings: ET 6249 (U 128), BE 65 and a further one at 47⁰ 20' N. and unknown longitude.
		2)	Report on torpedoing from AD 5398.
		3)	U-boat attack in DB 67 and FB 93 (U 154 ?).
		4)	British aircraft reported dinghy with 4 survivors in BF 4471 (probably a plane shot down by U 459 - see War Diary of 31st May).
	d)	British steamer "Lombardy" was ordered on the 28th May to deviate from her present route and proceed over FC 8230 and FK 1370.

IV.	Current Operations:
	a)	U 409 and 594, on outward passage, were ordered not to operate against the convoy reported by aircraft but, on the other hand, to utilize any opportunities for attack.
	b)	1)	It is intended that U 193 should operate off the Brazilian coast, objective - EQ 50.
		2)	U 126 and 105 were given freedom of action in the whole Freetown area.
	c)	1)	U 161 refueled from U 229. Both boats are proceeding back together.
		2)	U 377 cannot carry out escort of U 552 owing to shortage of fuel. This will be done by U 413.
	d)	None.

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V.	Reports of Success:
	U 126 - 1 ship 8,000 GRT.

VI.	General:
	The orders given, in view of the new situation, for the protection of boats against surprise aircraft attacks are summarized as follows in "Permanent Order No. 13": The danger of surprise by locating aircraft, particularly by night is great. The following basic principles should be observed by the boats: be as careful as possible while under way and at waiting positions - avoid losses. If the enemy is sighted then go into operation with courage and tenacity in spite of danger from aircraft, remain surfaced and ward off attacks of aircraft when necessary. It is, therefore, ordered that:
	1)	U-boats approaching and returning from the Biscay area up to 18⁰ W and in the approach area home North Atlantic up to and including square AL, upper third, will proceed submerged as a general rule. They will surface only for charging the battery and ventilating the boat and only by day. Surface run by day is permissible only in very good visibility which excludes the possibility of surprise. Boats should proceed surfaced as a rule on incoming routes. Only submerge when danger of aircraft is acute. Boats will proceed out in the morning and in at evening, so that the incoming route is passed by day. See Standing Order 483, Section D 1.
	2)	Special instructions will follow regarding passage of several boats together.
	3)	Procedure in the operational area North Atlantic, i.e. AL, lower and middle third, AK, AD, AJ, BC, BD, north half BE, CG, CF east half, under way and when stopped in position.
		a)	By night: One main engine slow to half speed and the other Diesel engine ready to start up, boat's ventilator switched off. Reason: to detect aircraft approaching by means of hydrophone.
		b)	By day: With higher cruising speed than before confirm that the boats is maneuverable and able to dive.
		c)	If weather conditions are unfavorable, proceed only submerged by day and night.
	4)	Procedure in coastal area os America, the Caribbean, middle and South Atlantic according to situation and decision of the Commanding Officer.
	5)	When operating against the enemy no restrictions as to surface run, attack is the most important factor.
	6)	When proceeding on the surface always keep radar interception apparatus and Flak guns ready for action and manned.
	7)	Standing Order No. 483, Section a) Fig. 2 and Section C) invalid at present. Carry out correction in pencil. Permanent Order No. 13, dated April 1943 and admonitory radio message 2303/22/48/165/259/379/416/718/845 is therefore invalid and should be destroyed.

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31.May 1943.

I.	U 66	-	Op(DC 10)	U 199	-	CE 16	U 413	-	BD 36	U 575	-	Op(AK 47)
	67	-	DE 48	202	-	Op(AK 11)	418	-	BE 60	592	-	BF 80
	91	-	BD 39	211	-	Op(DF 18)	435	-	Op(CD 81)	594	-	CF 38
	92	-	Op(DC 52)	214	-	CF 79	436	-	BF 40	603	-	Op(DF 12)
	105	-	Op(ET 60)	217	-	Op(DF 18)	440	-	BE 90	607	-	BF 40
	118	-	CF 37	218	-	BE 60	450	-	AN 31	608	-	Op(DF 18)
	119	-	BB 70	221	-	Op(CD 79)	455	-	BF 58	621	-	BE 60
	123	-	DH 12	228	-	Op(DF 12)	459	-	BE 90	636	-	AK 01
	126	-	Op(ET 60)	229	-	BD 86	460	-	ES 17	641	-	Op(DG 12)
	154	-	Op(FB 60)	231	-	BF 68	467	-	AL 16	642	-	Op(CD 79)
	161	-	BD 86	232	-	Op(CD 76)	488	-	AK 66	645	-	Op(BD 18)
	170	-	AN 31	264	-	BF 61	508	-	BF 40	650	-	Op(AJ 29)
	172	-	BF 40	271	-	AN 36	511	-	FD 37	664	-	Op(BD 36)
	177	-	Op(JJ 42)	304	-	Op(AK 46)	513	-	DS 93	666	-	Op(CD 73)
	178	-	Op(KY 60)	305	-	BF 52	515	-	ET 98	667	-	AL 14
	180	-	GG 43	308	-	AN 36	521	-	Op(CA-DC)	669	-	AN 31
	181	-	Op(KP 60)	336	-	Op(CD 81)	527	-	DD 87	707	-	BF 93
	190	-	Op(CA 80)	340	-	BF 80	530	-	BF 40	731	-	Op(AK 73)
	193	-	AL 18	341	-	AF 48	535	-	AF 48	758	-	CG 11
	195	-	Op(JJ 20)	377	-	BE 46	552	-	BE 46	760	-	BF 68
	196	-	Op(KZ 20)	378	-	BE 60	558	-	Op(CD 54)	951	-	Op(CD 58)
	197	-	GH 17	403	-	BF 52	563	-	BF 40	952	-	BF 93
	198	-	Op(JA 10)	409	-	CG 45	569	-	Op(DF 12)	953	-	Op(CD 57)

	On Return Passage: U 123 - 161 - 180 - 218 - 229 - 231 - 264 - 305 - 340 - 377 - 378 - 403 - 413 - 418 - 436 - 459 - 552 - 575 - 607 - 621 - 636 - 664 - 707 - 760.
	Entered Port: U 564 - Bordeaux.
	Sailed: U 403 - Brest; U 508 - Lorient; U 760 - 231 - La Pallice; U 952 - 707 - 340 - Bordeaux.

II.	Air Reconnaissance: None.

III.	Reports on the Enemy:
	a)	1)	U 459 warded off a double attack of 2 four-engined aircraft in BF 5121. The aircraft approached 5 times and the boats obtained an explosion on the first and a hit on the second. One plane shot down was confirmed by a special intercept message. No damage on the U-boat.
		2)	U 731 sighted in AK 7271 a single vessel proceeding at high speed and escorted by 2 corvettes and 2 destroyers, course 230⁰, speed 14 knots. After 7 hours' chase in vain she was forced to submerge by a destroyer. Contact lost.
		3)	U 513 fired in CF 7694 a three-fan torpedo which failed on type "Australia Star". Subsequent chase was without result.
		4)	U 193 reported on experiences over the Iceland Passage; twice radar with note, 9 times radar without note. Aircraft sighted 3 times. Several aircraft bombs and depth-charge detonations heard far away, twice Asdic search groups hydrophoned. No drifting mines.
		5)	U 198 sank in JA 1223 British vessel "Hopetarn", 5,231 GRT, course 270⁰, speed 13 knots.

- 446 -

			On the 31st May convoy pursued for ten hours at maximum speed. Before dark attacked by locating corvette, at night warded off aircraft attacks or submerged. No contact.
	b)	None.
	c)	1)	U-boat sightings: CA 9485, DM 6434, AK 6560, BF 4485 and 2 further ones in unknown position, probably Biscay area.
		2)	Depth charge attack on U-boat in BE 6899.
		3)	U-boat attacks in FA 37 and DB 67.
	d)	American U-boats on the evening of the 29th May in AJ 6891 and BD 1321.

IV.	Current Operations:
	a)	None.
	b)	New objective for U 118 - 440 - 758 and 592 is DG 44. These boats are to refuel from U 118 approximately in this area and then proceed southward.
	c)	None.
	d)	1)	U 563 was bombed by aircraft at 1650 in BF 4466. The boat was able to dive and requested air cover. Later she was attacked again and sent a distress message by radio. Boats in the vicinity were ordered to give assistance. Our own aircraft could not be sent in owing to bad weather conditions. If possible, however, they will be sent on the 1st June. Of these boats U 621 reported going to assist U 563. On the way, U 621 was also bombed and has only limited diving capacity.
			It appears, from a decoded aircraft message, the U 563 was sunk and the crew swimming in the water. U 621 broke off the search towards morning in view of fuel shortage. The first formation of Junkers, consisting of 8 machines, started at 0700 on the 1st June. The aircraft took rubber boats with then which could be dropped if necessary.
		2)	U 467 has not reported since putting out from Bergen. After receipt of a special intercept message of the 29th May regarding an aircraft attack on a U-boat in AE 58, the boat was ordered several times to give her position but did not reply. According to dead reckoning, she was in the proximity of the attack position. She must be considered lost.

V.	Reports of Success:
	U 459 - 1 aircraft
	U 198 - 1 ship 5,231 GRT.

			For Flag Officer Commanding U-boats
			Chief of Operations.
			GODT.

- 447 -

Naval High Command
2 Naval War Staff / B.d.U. Op.
Ref. No. Group Command 2968 A.4.
		21.May 1943.
Most Secret

To:	Naval War Staff/Chief of Naval Communications Service
	Communications Research Department
	Research, Invention and Patents Institution
	Naval Weapons Department
	Artillery Weapons Department
	Torpedo Weapon Department
	Communications Experimental Command
	Communications Testing Command
	Chemical-Physical Experimental Establishment, Kiel.

For Information:
	Admiral Commanding U-boats
	Captain U-boats, West
	Captain U-boats, Norway
	Captain U-boats, Mediterranean.

Re:	Effect of Enemy Radar in U-boat Warfare.

Enclosed herewith copies of "Effect of Radar by enemy operational forces on U-boat warfare and necessary countermeasures".

The purpose of this paper is to summarize the present operational situation and the necessary countermeasures from the point of view of Operations Control for all Departments which are or may be concerned with relevant questions so that there may be no false impressions through considering only a part of the problem which might adversely affect consideration of the problem as a whole.

The Chief of Naval Communications Service is requested to forward the enclosed 20 copies to Research and Development Departments outside the Navy, so far as possible or appropriate.


		For Flag Officer Commanding U-boats.
		Chief of Operations.

- 448 -

			Enclosure to 2/Naval War Staff B.d.U. Op.
			Group Command 2968 of 21st May 1943.

Effects of Radar used by Enemy Forces on
U-boat Warfare and Necessary Countermeasures.

			Most Secret.

The purpose of this paper is to summarize for all Plans Development and Experimental Departments the effect of enemy radar on U-boat warfare and the necessary ways and means, from the point of view of Operations Control, for counteracting them.

I.	General:
	1)	The power of the U-boat, which from the first idea of this weapon up to the present formed the basis for its operational capacity, is constituted by its ability to be able to escape being sighted by the enemy by diving or by reason of its narrow silhouette. This capacity enables it
		a)	to penetrate into areas under enemy control and patrolled by him and to remain there.
		b)	To approach the enemy submerged by day and surfaced by night within close range in order to carry out a certain and destructive torpedo attack.
		c)	To be able to escape a subsequent attack or pursuit.
	2)	If the enemy is successful in detecting the U-boat far away he will divert the essential targets for the U-boat (merchant ships and battleships, convoys) and, therefore, withdraw altogether from an operational engagement.
	3)	The U-boat which is sighted by, or its direction and distance away established by escort forces (aircraft, destroyers, corvettes etc.) may be attacked successfully by these. As the U-boat, by reason of its constructive characteristics and present armament, is hardly in a position to defend itself against these escort forces its damage and destruction is all the more certain when exact and early confirmation of the boat is possible.

II.	Situation:
	4)	Recognizing these facts our enemy has made every effort to counteract the fact that the U-boat cannot be sighted and to locate it with radar as accurately as possible on the surface and underwater.
		He is using various surface and underwater location means the physical and technical principles and practical use of which are not completely known in all cases, and the presence of which can only be confirmed in some cases by their effects.

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Strategic Effect:
5)	Today the enemy is enabled, by means of the great range of his location gear, to spot the U-boat already far away, and also to confirm at the same time scattered U-boats, so that he can ascertain the position of U-boat groups, patrol and reconnaissance lines and, in this way, gather information for a well-timed and extensive avoiding action by the convoys.

Example:
A group of 10 - 15 U-boats is disposed in a line abeam to the suspected approach of a convoy, at a distance apart of 15 - 20 miles (that is 27 - 36 km) from boat to boat. The area in front of the convoy route is patrolled by enemy reconnaissance aircraft for one or two days beforehand. If an aircraft locates one of these U-boats at a great distance away (i.e. 40-50 km., and more) it will, upon nearer approach to this boat, detect a second boat on the line and can - out of visual range of the first boat - approach the second boat. Even before reaching this boat it will detect the third boat of this line. In this way the whole line can, if the occasion arises, be detected by one aircraft on reconnaissance and data obtained for avoiding actions by the convoy, with out the boats in position being actually sighted by the aircraft. The convoy by-passes the patrol line and continues its passage without being sighted and attacked. Such avoiding actions have been confirmed continually during the last few months by other boats proceeding singly which have encountered the convoys by accident, and by other circumstances.

Tactical Effect:
6)	In direct operational engagements between U-boats and escort forces of the enemy, the enemy radar location has a more direct effect which is more paralyzing and dangerous for the U-boats.
	a)	If a convoy (or another worth-while target) is sighted by U-boats, the latter move ahead of the enemy, always maintaining contact at the limit of visibility, in order to assemble them at night at firing distance or by day to go over to underwater attack in the path of the enemy.
		If the boat is sighted or located during this operation by escort forces, on their part, go over to the attack and the boat is forced to escape this attack by submerging and, therefore, becomes stationary and inactive. In this way, even though the subsequent attack of the escort forces may not cause damage to the U-boat, the escort forces have fulfilled their main task, the target proceeds out of sight, the escort forces follow it sooner or later owing to their superiority in speed, the U-boat however is far behind the target and, if it finds the target again at all, will only be able to attempt a fresh attack after a very long period of time.
	b)	In order to be able to engage the U-boat before contact with convoys, the enemy sends out his defence forces, primarily aircraft, to the approach routes off the U-boat bases. The stream of incoming and out going U-boats and the concentration of traffic in the comparatively narrow area of the Biscay and North Sea offers enemy aircraft above all ample opportunities

- 450 -

			for detecting U-boats and attacking them by surprise.
	Radar Location Forces:
	7)	The most powerful and noteworthy types of enemy defence and escort forces are the destroyer and the long-range bomber.
		a)	The destroyer is able, in view of its range and speed, to escort and protect convoys or important units over large areas, to pursue a detected U-boat and to remain for a long time in the operational area.
			It can be equipped with very varied radar apparatus for surface and underwater detection as well as with large supplies of weapons for attack (depth-charges, guns, machine guns etc) in order to carry out attacks on a detected U-boat persistently and effectively.
		b)	The aircraft is, by reason of its speed and great height, the most suitable means for forward reconnaissance against U-boats, but is also the most dangerous enemy force in direct attack.
			While the destroyer or escort is nearly always sighted by the U-boat sooner than vice versa, and the approach for attack, therefore, is generally observed early enough for the U-boat to dive in good time and to attain a certain distance apart from the point of sighting, the aircraft can in many cases make a surprise attack. This capacity favors the aircraft above all in circumstances when it can locate the U-boat, without being seen, and run in, under protection of a bank of clouds or in darkness, without being observed until the last moment or even not at all, for a particularly effective attack with bombs and machine guns against the boat which is surfaced or just diving.
	8)	The U-boat is deprived of its most effective characteristic by radar location, i.e. that it cannot be sighted. Through this, possibilities for operations are more and more limited and the defence forces are definitely superior to the U-boats.
		U-boats today are exposed, even while cruising, to this enemy defence to a very great extent and suffer losses in operations which are now much to high compared with the successes gained.
		The solution to this problem is of decisive importance for the further successful conduct of U-boat warfare and, therefore, perhaps even for the outcome of the war itself.

III.	Location and Counter Measures:
	9)	The operational strength of the U-boat must again be made reasonably comparable with that of the enemy by,
		a)	re-establishing its "invisibility" by counteracting enemy location
		b)	improving its endurance and capacity for attack in such a way that the effects of enemy location can be neutralized.

- 451 -

10)	The problem of countering enemy location will, in principle, be best and most effectively solved if we are successful in,
	1)	Eliminating the pulses emanating from the U-boat or screening them in such a manner that the enemy can no longer utilize them for location purposes.
	2)	Destroying, diverting or disturbing the pulses sent out by the enemy for purposes of location, in such a manner that he is not able to make use of them.
	As long as this requirement cannot be met or can be only partially met, it is essential that at least the fact that the enemy is locating be confirmed at once (if possible even before the enemy can obtain any results) so that other countermeasures may be adopted. The possibility of confirming the enemy radar as regards direction, distance and type, as well as recognizing how successful is his radar location can render the countermeasures and defence measures in many cases so effective that the disadvantage thereof is practically eliminated.
	It must, however, again be emphasized that this solution is still only a partial one, since the prevention of our own attacks is not eliminated by merely establishing the fact of enemy location.
Radar Location:
11)	Out of all the known location methods of the enemy, radar location is used most frequently and effectively and it is the one which prejudices U-boat warfare to the greatest degree.
	The enemy, as far as has been ascertained by U-boats up to now, uses varied location frequencies from about 120 cm. to 240 cm., and possibly still considerably higher frequencies which cannot be picked up with our present gear.
	He uses pulse frequencies which are outside the range of acoustic reception by our radar interceptors and can only be determined with a visual indicator. By reason of very careful and short-term radiation of his location gear, the reception of the pulses sent out is made very difficult and is almost impossible with the present U-boat equipment.
12)	The elimination, diversion and effective disturbance of the enemy location pulses is made so difficult, by reason of the use of varied location frequencies, as well as by the technical considerations of the U-boat, that a speedy solution cannot be expected according to existing theories. However, this solution must be dealt with.
13)	Confirmation of enemy location as well as further details regarding it seems to be more possible. As in the present situation, a speedy solution may be decisive, this task must be given priority, even if it only effects a partial solution.
	The U-boat, therefore, must be equipped as soon as possible with gear which enables it to:

- 452 -

	a)	Confirm at once, while surfaced, any enemy radar location activity without regard to pulse or carrier frequency used and without regard to the duration of the radiation.
	b)	Determine approximately at least, the direction of the enemy location as quickly as possible.
	c)	Confirm, while submerged, the presence of the enemy location before surfacing.
	It is again emphasized that the solution of the problem by steps in the order as given above, is not only permissible but is necessary in view of the urgency of the matter.
	The use of disturbance and decoy measures, as well as every tactical countermeasure and defensive measure by the U-boat, is only possible as a result of radar interception. Fulfillment of the above requirements is, therefore, also necessary before these can be used.
14)	Disturbance of enemy location by jammers on U-boats is only of limited value as long as the enemy can pick up the boat itself by its jamming (direction indicator) since the boat is then attacked immediately and destroyed. Too much must not be expected either from the cooperation of several boats.
15)	When considering disturbance or decoy gear used from the U-boat, it must be taken into account that capacities for carrying gear of large proportions and the possibilities of using these against the enemy at sea are very limited. Further, it should be considered that attacks against a convoy does not take place in a narrow area but extends over hundreds of kilometers and lasts for several days and the individual boat is hardly in a position to predetermine the time and place of the attack.
Infra-red Location:
16)	Location by enemy destroyers and aircraft by means of infra-red rays may be considered certain in view of reports by the boats.
	These were observed up to now without image converter and, therefore , concern only infra-red rays with visible proportion of light. It is not yet known to what extent infra-red rays are used without visible proportion of light but this possibility must be considered now or later.
	While infra-red rays from the destroyer do not constitute any direct danger for the U-boat, since as a rule at least the U-boat can confirm successful location at the commencement of defensive measures by the destroyer, infra-red rays from the aircraft constitute a very serious danger, especially when they cannot be seen with the naked eye.
17)	Countermeasures are those primarily mentioned under 13), i.e. the U-boat must:
	a)	Confirm enemy location by an al-round detector
	b)	Be able to start defensive measures and countermeasures as a result of approximate direction indication.

- 453 -

		It does not appear urgent to confirm infra-red radiation from a submerged boat, before surfacing, on account of the assumed short range of the infra-red radiation.
	18)	It must be investigated whether camouflage or decoy measures against infra-red location are possible by devices being put out from the U-boat which counteract the enemy infra-red observation by their own strong beams. (Chemical substances which produce infra-red rays by heat development ("Infra-red fog").
	19)	Ultra-violet rays: The observance of a number of boats, when attacked and pursued by aircraft and destroyers, of a blue white light on these, indicates that the enemy in some circumstances is using location methods which somehow are connected with this light phenomenon. At the moment there are no reports from which further conclusions can be drawn. It does not appear out of the question that ultra-violet rays are being used.
	20)	Up to now there is no information regarding the use of location devices and processes on a magnetic, acoustic or thermal basis (e.g. utilizing the thermal rays of the Diesel exhaust). It is not out of the question that these are also being used.
	Underwater Location Means:
	21)	The danger which threatens U-boats through the use of underwater location means is at the moment less than that of surface location. The methods used up to now, Asdic and hydrophone, have certainly in many cases led to destruction of a boat, but the natural limitations of these location methods do not permit their becoming a real danger to the effectiveness of the U-boats. Avoiding measures and countermeasures as possible to a great extent. However, these methods of location (particularly the Asdic gear) prejudice the fact that the U-boat cannot be sighted in its own particular zone of protection, which factor is becoming increasingly important particularly in view of the fact that it is now more easily sighted on the surface.
	22)	The old requirement to destroy the pulses sent out for Asdic location is, therefore, just as important as ever. Confirmation of enemy location is not sufficient in underwater location, since the U-boat cannot escape from pursuit without any defence and also in view of its low underwater speed.
	23)	According to reports by the boats there is a possibility that the enemy has been using for about a year a method for underwater location in which locations are made by means of acoustic pulses sent out, these being similar to explosive soundings. This location method is said to have had some good success although its type and use are not yet clear.
		Other underwater location methods have not become known up to now nor is there any indication that there are any.
	Defence by our own attack:
	24)	If it is not possible with a reasonable time to eliminate enemy location to a very great extent, the operational power

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	of the U-boat can be re-established only by eliminating the defence forces themselves.
	The attack of a U-boat without the advantages of not being sighted and of surprise, is not favorable for method and type of the U-boat. It must, when forced to such an attack by conditions, be equipped with weapons which will hit the enemy vessels with great certainty and with destructive effect.
25)	Weapons for fighting off aircraft are in a stage of development and production at the moment, so that facilities in this direction are hoped for. The reaction measures of the enemy and the possibility even then of taking up the offense against the aircraft must, however, be given serious consideration.
26)	Requirements for an effective weapon against the destroyer have been stated in
		B.d.U. Group Command 344, Secret, of 31.8.42 (to Artillery Weapons Department) and
		B.d.U. Group Command 4302 of 12.10.42 (to Torpedo Weapon Department).
27)	In principle, however, the re-establishment of the "invisibility" of the U-boat remains the only requirement which is appropriate in view of the fundamental and constructive characteristic of the U-boat.

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High Command of the Navy
2. Naval War Staff/B.d.U. Op.
Ref. No. - Group Command 197 Secret - A2.
			S. O. Only
Most Secret.
			13.May 1943.

Orders for Operation "Dakar"
for U 214.

I.	Operation: An extensive mining of the convoy routes off Dakar is to be carried out.

II.	Enemy situation: According to present reports and observations by U-boats, large numbers of vessels and warships are to be expected going into and coming out of Dakar.
	1)	The Americans are continuing large-scale extension of the harbor of Dakar. Dakar, therefore, assumes special importance as a base for U.S.A. fleet units and as a repair harbor for ships damaged in mid-Atlantic.
	2)	Regular supply convoys from America for the extension of the harbor and the units stationed there are to be expected.
	3)	Convoy traffic has been reported from Dakar to Casablanca and in direction of Freetown.
	4)	"U 175" (Burns) reported from the Dakar area in December 1942: "Moderate air activity by day, by night radar (vertical 140 cm)"; locations by land on other bands must, however, be expected (see Situation report of Flag Officer Commanding U-boats regarding radar in U-boat warfare - B.d.U. Group Command, 2,555 April 1943).

III.	Mines:
	1)	15 SMA with 400 AT, time setting 80 days, safety gear on sinking minimum time, clockwork arming switch at 24 hours. Depth-setting minus 15 m., period delay mechanism one.
	2)	Maximum water depth at which mines may be dropped 350 m., minimum 50 m. Distance apart of mines 400 m.

IV.	Carrying-out Operation:
	1)	Boat to put out according to Order..., passage to be calculated in such a way that the operation can be carried out at about time of full moon.
	2)	The mines should be laid in 3 groups of 5 mines each according to enclosed sketch.
	3)	Any deviations in laying mines are left to the discretion of the Commanding Officer according to the enemy situation observed or notified. The time at which the mines are laid is left to the Commanding Officer after investigating the area.

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V.	Report:
	Report should be made as soon as possible after carrying out the minelaying, but from at least 100 miles away, by means of a short signal.
	In this connection A F K P = "have carried out minelaying off Dakar".

VI.	After the mines have been laid a further order will be given by W/T.

VII.	Operational Order "St. George's Channel" of 17.4.43., is invalid and should be destroyed.


		For Flag Officer Commanding U-boats.
		Chief of Operations.
		GODT.


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