The Battle of the Atlantic continued as intensely as ever. German radio intelligence meant they often had a good idea of when Allied convoys would be passing. Long lines of U boats would string themselves out across the probable path of a convoy. Once one U-boat had made a sighting the others would be ordered to move into the attack. In early May 1943 28 U boats of ‘Wolfpack Fink’ had congregated in mid Atlantic to find the Allied convoys.
Having found the convoys it still took considerable skill and experience to penetrate through the screen of convoy escorts to get in a position to attack the merchant ships. The number of U boat crews with the necessary skill and experience was rapidly diminishing. Whilst the Germans could build more boats they could not find experienced crews to man them. Many of the men now serving on U boats were no longer volunteers for the service.
Kapitänleutnant Hartwig Looks was on his third war patrol commanding U-264, and later gave this account of his part of the attack:
[J]ust before dusk [on the 4th] I was successful in finding a convoy proceeding in a south-westerly direction, too. And it was not really the convoy which we expected, but another convoy going over to the States, and the weather was not very convenient — we had rather rough sea – but we tried to close in to the convoy and fight off the heavy sea.
And we could do it: we could come closer and when it was night, during the dark time, we closed up to 5,000 metres and we could see the whole convoy proceeding in three or four columns (I don’t exactly know). And on the portside, where I was proceeding at the time, we sighted two escort vessels, smaller destroyers also, and I tried to find a good position for attacking the convoy.
And it was a bit difficult due to the bad weather because our binoculars were absolutely wet from the overcoming sea and from the over-coming waves, and so we had to give the binoculars into the conning tower (you see, the watch of the submarine was standing on top of the conning tower and we gave the binoculars down and they were cleaned there and they gave them back to us, and so we could see for two or three other minutes, and then we have to do the same because the binoculars were wet again).
But after a while I had a good position for attacking and I had the chance to slip through a gap just through two escort vessels and I could close into the portside column, and I had the chance to fire four torpedoes.
I torpedoed two ships, each with two torpedoes, and one of the ships, well, it didn’t explode, but after the explosion of the torpedoes another big explosion happened on board of the ship. Perhaps the boiler also exploded, and in our glasses during the dark night we could observe that this ship was sinking very quickly.
Then I turned around with the submarine to fire the stern torpedo, but this torpedo had a malfunction and it ran straight on the surface with a big, white, shining [track] against the target ship but as it didn’t run with exact speed — much slower than expected — this torpedo passed the target ship behind the stern and came into the second column of the convoy and hit there another steamer.
But I couldn’t observe any result, just the explosion of the torpedo, because at that time one of the escort vessels certainly picked me up and got contact with me, and so I was forced to submerge and get out of the way. This escort vessel depth charged me for some minutes and then joined the convoy, and I had the chance to recharge two of the torpedo tubes in the bow of the boat.
After about one hour I submerged again and proceeded into the last bearing of the convoy where the convoy disappeared and I was once more successful to get contact with the convoy I proceeded on the portside of the convoy to a position where I had the chance to attack the convoy, and once more I was lucky by slipping through a gap between two of the escort vessels and closing into the port column of the convoy, and I fired two torpedoes and both torpedoes hit the target ship.
And then the escort vessel was alerted and closed in about 1,000 metres distance. I had to disappear. I got once more depth charges for about one hour without hitting me, but this happened just before dawn, so I had no chance to find the convoy once more during the dark time.
See a 2003 interview with Hartwig Looks, an English transcript is available. One of Looks U-boat messages, encrypted by Enigma, defied decrytion during the war was not finally decrypted until 2006, using the resources of the internet and modern computing. See bytereef for the story.