3d Water Simulator

Hello Everyone,
For a project, I want to be able to simulate water. I realize that this is a very difficult task, but was wondering if it was possible to do with some hard work. I need to be able to have a buoyancy engine to start out, at least. Is that a viable goal? Just wanted a push in the right direction, or an absolute no.
Anyway, good day to you all.

If anyone cares, this is an excellent forum
http://forum.unity3d.com/threads/buoyancy-script.72974/
It really works well