I have decided to create a specific thread for this add-on because it will be available soon not only for Smart Water, but also for everyone else, and will be working for any water you want to use. There are some cool feature upcoming so follow this thread if you want to know what I am doing. What is the Underwater Add-on? This is an universal system to switch to underwater in 3d. It features an unlimited number of switches that can be assigned to anything (not on Mobile, a specific more limited script is available for mobile) and therefore can handle anything. For example you can assign a hi-pass filter to the underwater switch to turn it on when you go underwater, or run any of your script or post processing filters. Also this add-on has a nice underwater shader that is Open GL2 compatible, so that the water is looking great from under. It manages the fog color and distance, and restore automatically the settings when going out of the water. It features some sounds. It has some cool post processing effects like blur, distortion and a specially crafted water drop animation when going in and out the water. It handle the projector caustics on the underwater ground.