On the 17th November the U-Boat U-331 was spotted on the surface by a Coastal Command aircraft from No.500 Squadron in the Mediterranean. This was the U-boat that had been responsible for the sinking of HMS Barham a year earlier. An immediate depth charge attack damaged the U-Boat so that she was unable to dive. Other aircraft arrived and when attempts were made to man the 88mm deck gun and escape on the surface the U-boat was machine gunned. It was at that point that a white flag was raised and the U-boat appeared to surrender, lying stationary in the water.
The remaining events were pieced together by the Royal Navy Naval Intelligence Division after interrogating the survivors:
“U 331” then abandoned all attempts to make land, as her propellers were practically exposed. The ship’s company tended their wounded and “U 331” remained stopped. Some of the men tried to make rafts out of sections of the deck covering, their rubber dinghies having been destroyed by blast from the depth-charges.
Shortly afterwards, a further “United States” bomber made its appearance, accompanied by one Spitfire, and circled “U 331” several times. Several other British and United States aircraft also appeared. Some survivors said there were 15 or 20 of these.
At this moment, although the white flag was still in position, “U 331” started up her Diesels once more. This made a loud noise, especially as the propellers were more than half out of the water, the exhaust plainly visible. Several survivors said the responsibility for this action lay with an E.R.A., who acted without orders, but Tiesenhausen insisted that he had himself ordered this and it was therefore his responsibility.
Apparently observing this, a Martlet (described as a Spitfire by prisoners) flew towards “U 331” from port and machine-gunned her. Its gunfire penetrated “U 331’s” conning-tower, killing some and wounding others. Some sprang into the water in alarm. Tiesenhausen and his Second Lieutenant, Leutnant zur See Hartwig, were on the bridge and were both wounded.
What survivors described as a biplane then approached them from starboard and fired a torpedo. The torpedo-track was clearly evident and Tiesenhausen ordered hard-a-starboard, but it was too late. (N.I.D. Note. This was an Albacore aircraft from H.M.S. “Formidable,” which later reported that one 18 in. Torpedo Mark XII*, Duplex pistol , set to 12 ft., speed 40 knots, was released 700 yards from the U-Boat. The U-Boat disappeared after the explosion of the torpedo and a second explosion was observed under water and wreckage was seen.)
The torpedo struck “U 331” on her starboard side, killing 32 men who were still below. The remainder were thrown into the water and some were rescued by what they described as a United States flying-boat which alighted nearby. When they recovered their senses, there was no sign of their boat except wreckage and oil.
The attacks by the Martlet and the Albacore were observed aboard “Wilton” who was, however, still some 10 miles away and was not in time to prevent the final torpedoing. A Walrus flying-boat then appeared on the scene picked up the survivors, about nine in number, endeavoured to take off but found that her cargo was too heavy. She accordingly put some of the men back in the water and took off with the remainder.
Those left swimming were picked up by “Wilton.” Prisoners said that the destroyer searched for a long period for further survivors, but found none. A man named Karls was brought on board dead. Prisoners, especially Tiesenhausen, were all very bitter at what they termed the unfair action of the “United States” bombers in machine-gunning their shipmates swimming in the water.
They all admitted, however, that the aircraft which fired at them when they later started up their Diesels was quite justified in doing so. (N.I.D. Note. There is no evidence that any United States aircraft were concerned in these attacks.)
For the full report see U Boat Archive.