-46-
 
    PG/16423
    3/C Ritchie.
  Copy No. 171.  
Top Secret.    
 
     
 
                   Current Order No. 84 (August)
 
     
          Today, by using long distance reconnaissance planes and aircraft carriers, the enemy can bring in aircraft to attack on a D/F/ bearing in all parts of the North and Mid-Atlantic as well as in coastal waters.  Therefore danger of being D/Fed has become more serious for U-boats using W/T.  Inaccuracies of bearings of 50 to 60 nautical miles are corrected by the radar of the aircraft, see operational order No. 243.  Hence the following notifications:  
     
  1)  Make use of definite recognition by the enemy (sighting, attack) to transmit messages.  
     
  2)  If it is necessary to use wireless at other times, a special watch must be kept by the look-out and wireless operator, after use of W/T.  Remain submerged for several hours after a surprise attack alarm.  
     
  3)  In handling W/T, care must be taken to tune in without radiation.  
     
  4)  The danger of being D/Fed is less on alternative frequencies.  For the use of these see operational order 208.