Details about the attacks not yet attributed to an individual U-boat are unavailable but based on the war-time assessments it is unlikely that any of these attacks resulted in the destruction of a U-boat. It should be noted that the two attacks graded “H” gave insufficient evidence for the presence of a submarine, whereas the third attack was considered unable to have caused any damage to the submarine believed to have been present.

In addition to the Allied attacks mentioned above two partly corrupt war emergency reports obviously originating from German U-boats were monitored by German and Allied radio stations. At first a corrupt signal was received at 0539 on 16 January on 'Diana' service, stating 'torpedo hit, boat seriously damaged, is sinking, can only be held for a short time'. Unfortunately, information on the position and the signature was corrupt and could not be decrypted. At 0814 on 19 January another war emergency report was received corrupt in the 54-metre band, stating 'torpedo hit, confidential documents destroyed. Boat seriously damaged, is sinking. Can only hold her own for a short time now'. Again the square position was unclear and the signature remained unknown as the signal strength diminished rapidly at the end of the signal.

From the description of the results achieved in all attacks graded “A” or “B” during the time span under review there can be no doubt that all five U-boats could be considered sunk or seriously damaged. By plotting the most likely positions reached by U 305, U 377 and U 641 at the various times of attack, it is most probable that the attack by HMS Violet on 19 January 1944 was in fact directed against U 641 which should have stayed around square BE 2515 at that time. The distance towards the position of attack is only 30 nautical miles in northerly direction, disregarding possible navigational errors. Thus the location of the sinking is on the edge of the operational area assigned to U 641 at that time. U 305 should have stayed at least about 75 nautical miles to the south and U 377 is expected to have already passed some 24 hours earlier to the west of the position enroute to its attacking area in square AL 9798. Thus the decision of the Assessment Committee on the loss of U 641 is found to be correct.

Using U 377's last report at 0814 on 15 January 1944 from square BE 5748 as a reference, the attack of HMS Wanderer and HMS Glenarm two days later took place almost exactly on the boats direct course line towards the centre of its assigned attacking area around square AL 9798. The remaining distance between its last known position and the location of the attack is about 220 nautical miles, which equals the boat's mileage to be expected under the prevailing conditions and the given order to use economical speed. Thus it is very probable that it was in fact U 377 that was sunk by the two ships on 17 January.

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