Well, isn't that a bit hard? and another idea, Paul. If you want currents... Why not simulate a round world... where if you reach one edge you pop up on the other side
Why not copy the awesome design we have now
(Earth) jkz. But, Paul didn't your plan include dynamic water... where if you built a damn, the water would find another way to go?
Dams would effect flowing water... ie: the rivers/streams between bodies of water. If you put a dam in a body of water then it doesn't really do anything but sit there.
@Moonkey, it's not me making the submarines... it would be the players. I do plan to determine if objects are water tight because I'd like ships to sink if they have holes in the bottom... I'm not sure I'll be able to do it, though.