Was thinking of making a mod for far future submarine combat. Trying to figure out grounding and breaching(I figured a world requiring only subs would have to reason for no surface ships y logic deadly kill sats or maybe Europa.) meaning ramming and dodging would be important. Would add a tactical depth. I was thinking of using the water depth from Battletech(1-4 using a d4 to mark depth) going to a five would mean grounded and a 0 breach.