A major sound mod based on Pacific Aces and other sources has just been done. I don't have my computer handy so I can't listen to it, but it looks pretty good. PA used several different submarine movies to good effect.
http://www.subsim.com/radioroom/showthread.php?t=108512
Ducimus, did you edit the
U-571 file at all? The annoying thing is that he sounds the klaxon
three times instead of two.