My hopes that my game to include a full water surface simulation, controlled by a 3x200 array, have been properly dashed (probably not totally unexpectedly after my first trials....). After a lot of event optimization and short-cutting I decided it was just not possible. Asking javascript to do 3 equations on 600 array cells in a lot less than 16 ms was just not going to happen. Even trying it on MadSpy 's NASA spec hardware proved too much, and I suspect that European power grids noticed the time of the testing....
So plan B has been implemented and, for anyone playing a game, the visual appearance is probably just as good. Oh, and there is no discernible increase in cpu load. Phew!
Here's what it looks like now (I'll leave the gif above for a "look at what you could have won" comparison). You can see it momentarily on action in the demo, just before the piranhas eat you....