Volumetric slab of water (positive) + glass cube (negative) Group the two together and place the camera inside the negative cube. Camera position should be at water level. You may have to adjust the angle of the sun a bit too. Bubbles are just sphere's with glass bubble texture. Splash is a terrain mesh with water texture. Adjust field of view until it looks right. Sorry I don't have a formula for this, I just do it by eye. I hope this helped a bit though. Good luck.