Doog: if the world of the four stacker appears odd, track down one of the WWII submarine memoirs that recounts duty on an S-Class submarine (nicknamed Pig Boats without affection.) Six of ten were lost in the Pacific before being withdrawn from service in late 42. Pig Boats did, however, use old torpedoes that worked - a problem that the USN was slow to deal with in the Gato class subs and all of their destroyers. This allowed S-44 to sink the IJN heavy cruiser Kako - Japan's only loss at the Savo Island debacle.