Great thanks guys, I think im gonna try the BARF mod first. I remember that being an early mod and I dont want super torpedoes. I did some more research and it seemed that two torpedoes would usually sink a 7000 tonne ship etc, three for battleships. This obviously depends on where you hit it, I have not read much books on U-boats or general submarine warfare during WW2 and it would be great if someone would be able to clarify this or even actually recommend some good books.
Thanks