kitten: I played with your suggestions, and while the quality of the light beam got better, it still won't cross the water. Note how it falls on the sub and the fish. But nothing in between. In the Volumetric Options, the Intensity is all the way up. Quality Boost is all the way up. Show Smoke/Dust is enabled and the S/D settings are up to [about] 5.0...so the question remains: why won't the beam cross open water?