That's a cool gesture of you, Doug.
I've just thought of something else, but that wouldn't throw the light on all ground stuff and there's another problem. It's possible to convert the wave displacement to a mask, after stretching it in Y and rotating by the sun's angle, that could work as a mask for additional illuminated cloud, hence 'rays'. But the origin wouldn't stay the same after rotating, so there's a problem.
I don't know how it would work on an exact copy of the water layer (some masking function added of course) with an invisible setting, but visible to other rays. Would that still throw a shadow in the water? Being exactly where the water plane is you wouldn't have reflection or shadows on top. You'd only need to tell the cloud to receive shadows from surfaces. But the water plane has shadows turned off, for obvious reasons, so that may not work.
And increasing lighness of the shadows parts to the needed value for 'normal' light would make the 'beams' and caustics light up, relatively. I'll try something like that later and upload a file.