It's hard to top Chain Reaction, Basic Channel & R&S... and the main recent ones in the dubby realm have been named as far as I'm aware. Might be worth looking into Yagya, Monolake, GAS, Intrusion, but all are more or less related to either BC or Echospace...
If you want more variety in your wateryness however, here's some more that allways made me think of water.
Soundhack - Double Hammer
and some elektro, obviously since no one actually posted any drexciya yet, that has to come first...
Drexciya - Hi Tide
Luke Eargoggle - I'm your magic man
And some ambient. More on the dreamy side, and very much related to BC & the likes again...
Vladislav Delay - Anima
c.