[thom]

To an extent you can get away with just sampling the output of the water shader to work out the water's effective height at any given point. Big changes in height, or buoyancy for non-static objects, indicate bigger angles hitting the waves and you can fake some splashes with particles while the wave itself just gets occluded. Apply forces at just three or four points and you can make a boat rock pretty believably on top of this kind of water.