I don't know where I got the idea for this picture but it turned out quite well I think.

Basically I dug a trench in the terrain editor.and played around for hours trying to find the right texture and bump hight,then added a water plain,once again I had to play around a lot with the settings,textures and bump hight to get the right effect and perspective.

The planes also took a bit of doing ( actually close up they look terrible, but from a distance not to bad.)