Low water for higher FPS still?

With the old engine we used to have to put water on 'low' if only flying over land to get higher FPS because the water was rendered over the entire 'sandbox' with the land over the top of it.

Do we still have to do this or is water only rendered where there is water with the new engine?

Old habbits are hard to break - I'm still fining my self putting water 'low' if only flying over land.

I am sure water is still rendered under all of terrain (in Caucasus map at least, I have never tried to look "under" Nevada terrain :D).