True story: I read in a book, about a Uboat picked up a survivor unconsious, they took him below and looked after him, hrs later he woke and realised he was in a submarine, he then turned to the german tending to his wounds and said boy am i glad you guys rescued me their was a bloody uboat in this area if i could get my hands on those nazi bastards i would strangle them. He didn't realise he was in a uboat but thought he was rescued by a british sub. They feed him gave him a ciggarette and told him to go up on deck, they never let on he was in a german uboat but just listened to his bemoaning about the nazi scums and how he would love to kill them all. Not one of them spoke to him until it was time to go up the ladder one of them said when you get up on deck have a look at the captains cap. ( which i presume would show the nazi symbol or cross?) He went up and according to the author the guy was shocked & speechless at what he saw and realised he was agmonst germans!
They put him in a liferaft threw him a carton of ciggarettes, water bottles and a map and let him go. Then the captain said something along the lines of if you head east your make your way back to england - good luck and they left the area, all the while the british guy looking stunned, but managed to say a quick thankyou.
Ive still got the whole story somewhere, i have so many uboat books and have read many storys such as this one, alot of uboats did help survivors some would just throw them ciggarettes or water or give them directions. Later on in the war Hitler found out about what some uboat commanders were doing & ordered no more helping survivors.