Personally, I don't like current water at all. Current "water" swirling material could be good for Quake's murky basins, is not good for simulating the kind of water we usually meet; even more, it behaves differently in FFP and GLSL renderers, which somewhat breaks the "mansion" map (and maybe some others).
I've been thinking about it a lot, considering various ways, but was always returning to the same thought: we can use the same approach as in Cossacks, using the procedural water simulation to create random, realistically-looking water. And they were doing on 100 MHz Pentium, remember? It was fast enough.
Finally, today it somehow dawned on me, so I've understood how to make simplest possible fluid solver, so after a few hours it was written, tested and tweaked to look like real water (it is not physically correct, but is based on real world hydrodinamics).
It is relatively fast: unoptimized version, being written entirely in Java consumes only about 1% of CPU while rendering 256x256 heightmap at 20 frames/sec.
I'm attaching it to the post, so everyone could play with it and say whether it is good or not. Requres Java Standard Edition (SE) 1.6 or later. Download, extract fluidsolver01.jar from the archive and run with "java -jar fluidsolver01.jar"
Click or click-drag mouse to disturb water, there are no built-in wave generators for now.
