"American subs available are the S-18, S-42, Salmon, Porpoise, Tambor, Gar, Gato, and Balao classes. Sadly, a personal favorite from Silent Service II –
the oddball Narwhal – didn't make the cut, despite its giant twin 6” guns mounted on the fore deck. In general, this is actually one of the small problems with the game – there isn't that much variety to American designs. "
OMG! 
Keel haul em!
He called the Narwhal oddball!