Nice! I do the same thing but using PSP instead of GIMP. Really like those fields. A tip for your water is to just color the area blue and then overlay a semi-transparent png on top of it with water/wave textures. Something like this just as an example (hard to tell, but that is semi-transparent and will pick up your color underneath it. But there are larger, better quality ones out there (that was a lazy google search result. haha).
