I like this pretty well overall.  
Some critiques - the sand seems too orange to me.  Is it my monitor?  Another thing - while I'm certain you did not do any "cheating" (by using other programs to touch this up), the shoreline looks fake.  I don't know why, but it needs...oh, I know.  It needs some foam.  
Hope you know I'm only being extra picky, since I think this is on its way to something very cool.