hey, at least you survived
one time i was in the northern tip of england, AM51 was it? convoy coming throuhg, i could hear them but i could not see them, there was heavy fog, rain, u name it. the visibility must have been 100m because a few boats were upon be before i saw them. needless to say I got annoyed with the situation and since nobody could see jack ****, I surfaced and chased down the targets, using impact pistols and doing 15 second calculations... real rough estimate stuff. anyways this was in a type VIIB, 4 torps, I think i got 1 or 2 but it wasn't a good night. eventually I just slinked off because I couldn't see any targets.