Holy crap.... Hummel, nice piece of work!
I'm working on a new project that is 60 square miles.
The Island is 45 miles long and is "Isle Royale" a National Park located in Lake Superior.
I would love to put you system to a major test.

I imagine I could use the same features that I use with my multi terains such as terrain lod and cashing
as I see that there many verticies to allow the wave action.
I believe that I could get it to work but I assume the terrain edges might be problematic.

I get 90 fps looking out to sea and 35 fps with the full island across the whole screen.
The system I am testing it with is an old Sony Vios with Windows XP,
Intel Penium (R)D CPU 300GHz and 2.0 GB of Ram with a new GeForce 9800 GTX+

I do notice that the tree palms look very strange under low light conditions.
I really appreciate your project and your work. Please update me when you can...
When might it become available?
Thanks for your efforts...