Tutorial: Create realistic, tropical water in Cycles

Ever wondered how to make realistic, beautiful, turquoise water in Cycles? Well Here’s how!

Tutorial: http://imgur.com/a/4nSuO

If you are lazy, you can just download the blend file:

This is the result:

It works, so that it becomes more dark blue, as the water gets deeper.

When you are on deep water, it looks just as realistic.

-Is realistic
-Is render-efficient
-Is easy to make

-Does not work underwater
-Requires the sea bed to be textured in a specific way (more on that in the tutorial)
-Is not animated (can be done though)

Needs some work but well done.

See if you can improve on that.