with New ui (ok, boat pitching up) :
with New ui (dissapear, boat pitching down)
Without New ui :
Without New ui (just before the boat reach completly the surface) :
So the newui change something somewhere about that.
The new ui parameters is bad, as when you can't use your deck gun, you can't have men to the flak gun too
I don' find the option of cfg to edit to avoid that.