In this tutorial (Part #1 of a series), I will show you how to create ocean meshes and set up the lighting. in Part #2, I'll cover materials and in Part #3 I'll render, and composite it.
NOTE: This Ocean will not be animated as there are still a few bugs with rendering animated Oceans (at least HD ones).
Oceans were once very difficult to create. As much as I tried, I couldn't find a great method or secret to creating realistic oceans in Blender but, with the release of Blender 2.605, things got a lot easier with the new Ocean simulation modifier. It is surprisingly easy to use and creates stunning ocean animations. The basics of using it are covered in this tutorial!