looks much better w/o the reflections. But the island map is bad, sorry. If I'm saying that, it'sbecause I believe it can be way better, not to be an ass. Otherwise I wouldn't even bother posting.
That map has obviously been photoshoped, then use as both a diffuse and bump map, the result has been rendered/backed up and then has been reassigned to the island through a top UV mapping ( if I'm wrong, I'll make you a map

).
You're gonna tell me it's easy to criticize when you've not done it yourself, but funnily enough I've done about the same thing last month ( for my new Oleon Wars project ):



( it's not top notch, but it worked for why I needed to do with it, and the choice of colours is made to make it cartoonish )
I see a few ways of improving the thing:
1) make your work based on the shadows of the mesh render ( paint with your brush as fusion, low opacity, and be patient ), force on the darker parts ( canyons ). Use the hard brush, not the one that fades on its borders.
2) paint the peaks with brighter colors ( can be easy to overdo it, so mght be wise to do that on a separate layer )
3) don't hesitate and try fancy brushes for the green parts ( plants )
but, the most important part:
4) don't rush the map. On landscapes, Maps ARE the most important part, you can get away with a low polycount, but not with rushed maps.
Oh, yeah, my island is meant to fly, but not yours, so I'd add an additional layer and would paint the foam along the island' edges, would make the thing blend better with the sea ( think about having the most outer border unregular and blue as the ocean, or you'll still have the hard edges and that will defeat the whole purpose of the thing ).
Voila, hope it helps.