Gneiss, that rocks, and the picture is crystal clear. Great scene.
Do you have any light blue sloped bricks, because then the "waves" could have been crashing on the rocks. Just an idea.
My opinion: very good, but I guess the grey tiles at the base of the rock are somewhat strange... yellow, for sand, perhaps? Or perhaps the rocks could end at the sea... Very nice anyway.
WOW! Brilliant work man! I love the change in colour on the water, I know your not the first to do it but it still looks great :D and the rocks look magnificent!