Maybe we should sort out if the
super ultra water and skin visualization is what makes a subsim exceptional or moderate.
My priority is clearly not the graphic part. This is only the ice on the cake.
Modularity, realistic crew and technology behavior, good small and big missions and different multiplayer options (one boat, several player roles?) are what awakes my interest into this idea/project. The more realistically I am marooned into that tin can, listening for depth charges, frightening, the better is the game. IMHO.
Many important details were already mentioned. Just one more: If it would be possible to cover with one basic vessel engine all the WW1, WW2 and cold war boat developments: I wouldn't only buy such a game and related updates, I also would participate in a crowd funding pot.