Youll have to experiment, some water texture do this and some dont, anyway make a cube map 32 units above the face of the water, double click on it in 3d view, click brush faces, then the dropper button and select the face of the water. Build your cubemaps and wah la reflecting water as best as it gets in source.
There's more to just good looking water than the water texture. I doubt that there's anything special about the one in the Lost Coast, it's just that they've added a nice coastline, lots of detail and HDR as well and that tends to make it look better.
dont use youtube they're either people who cant talk... or 3klikphilip