(typed in soluble ink)   Copy No. 135__
     
 
Secret
  
 
 
 
Standing War Order No. 171
 
 
     
 
Experiences and Observations
 
     
 
1) Use of the Enemy's Air Force against U-boats.
          The Air Force is a dangerous foe to U-boats.  The enemy is using it to a great extent for the purpose of U-boat defence.  As it is operated in part from aircraft-carriers, it must be reckoned with in very distant areas of the open seas.  The English Air Patrol is flown even in very bad weather.
  Up to now the presence of aircraft-carriers has been established:
    In the western sea area Shetlands - Faroes,
    west of Ireland,
    south-west of Ireland,
    west of the English Channel,
    west of Gibraltar.
  The aircraft bombs have large explosive charges and time-fuzes.
2) U-boat defence in coastal waters.
          The enemy has a large number of trawlers, cutters, motor boats and other small craft in the U-boat defence service.  Their equipment is not uniform.  Some of them have listening or position-finding apparatus, the efficiency of which does not however appear to be great.  They try to avoid recognition as watch vessels by their appearance.  They are often camouflaged by irregular patches of colour.  At night they do not always sail with darkened lights.  They often show a red, white, or green toplight.  By the kind of position lights their arrangement (far apart, close together, high, low, bright or dull) they try to deceive as to their nature and size.  Be on the lookout if several are working together.  In that case they usually have nets laid out.
          Their task is not only direct combat with U-boats; they are to keep any boats detected under water until the arrival of well-equipped pursuit units.  Look out for single darkened watch vessels between steamers carrying lights.
3) Attack on U-boats.
          When U-boats have been detected (sighting reports, SOS and SSS reports by steamers, notification of sinkings)
  a) aircraft are despatched, to attack and keep the boat under water;
 
 
 
 
 

 

 
 
 
 
     
     
 
  b) then destroyers or other pursuit vessels join in;
  c) the warning signals to shipping are sent out relatively quickly.  Traffic is diverted.  While merchant ships are ordered to avoid the suspect area, it is to be reckoned with that any U-boat decoys in the neighbourhood will at once make for the areas where U-boats are suspected.
    It is therefore proper, when the presence of the U-boat has been betrayed:
    a)  to leave the area for another.
    b)  to be particularly wary of any steamers that may still be met with.
4. Behaviour of enemy merchantmen:
    English shipping has received the following instructions:
  a) Every German U-boat is to be attacked with every means available; it is to be rammed, and if the ship is equipped with depth-charges, these are to be used.  The possession of depth-charge apparatus by their merchantmen has been established on more than one occasion.
  b) The ships are not to pass through waters near the coasts at night; ships coming in at dawn are to lie off their ports of destination.
5. U-boat decoys and deceptive devices.
  a) The existence of U-boat decoys has been proved.  Steamers of every sort and size can be converted for the purpose.  Their collaboration with aircraft and m.t.b.s has been observed.
  b) It has been observed in many cases that merchantmen seek to mislead as to their course and size by displacing their masts or sailing lights, and that they protect their bridges by sandbags against gunfire.
  c)* British merchant vessels in the South American service, which have hitherto been mostly painted grey, are now in some cases making their appearance resemble that of neutral ships, especially Italian.**  Besides this they carry large metal plates or wooden boards with neutral flags painted on them, which can be fixed to the sides in case of need, to give the appearance of a neutral ship. 
            It may be taken for granted that all enemy merchantmen carry out the same sort of camouflage.
     
     
                                                                            signed  Dönitz.
     
  c)* Slip in ordinary typescript pasted at bottom of page, with the words "especially Italian" crossed out in red ink, and signed We 28/ii.