Diver idea for the crew
 

Hello, I was wondering if would be possible to implement a frogman between the crew of SH4 subs,in order to be able to develop spy missions on the bases ocupied by japs.This way the flooding compartment could be simulated with the frogman going out the sub and coming back.I leave to Ubi developers what the diver could do once outside,swimming dived to the shore,camouflage,etc.

I believe in SH4, the sub might well be involved in carrying commandos/frogmen for a mission, but the game is not set up to follow their actions. You would either be deploying them for a mission or retrieving them after a mission.