For f2f games, you need professional equipment, if better skills and experience is not enough, you need to be sure.
It’s even better than low luck
Check out the dice cheat section.
Just as other ships may, submarines may also move out of a sea zone where they begin their turn with enemy ships, even destroyers. The destroyer doesn’t stop the sub’s movement, as the sub didn’t enter the sea zone - it started off there.
Put that in the FAQ