Who gives a SH@t as long as it is fun to play.

But really, lets make the base game fun and get some goals going before we talk about 'swimming and underwater content'.

I don't care if water kills me in one touch as long as it is fun, gives me a goal, and brings in enough players to sustain it.
(See Mario, or Assassin's Creed).

This entire discussion is a waste at this point in the game. Glad I could add a little more waste to it. That's what the internet is for though..... (and increasingly these forums)