This is amazing!!
And what you were saying with how to do water...
The light waves tend to fade out. To make it look really cool have the light just come from one side at an angle. That would look really cool!
Kinda like this photo:
)
And maybe have the water that's closer to the surface be lighter, and as you go further down have it become darker and darker? Because the sun's rays cannot penetrate too far into water.
Well that's all the critique I can give because this looks awesome! Maybe the best artwork I've seen in a while!