Made in 2.65 and Gimp.
Rendered with Cycles.
Textures from CG Textures.
I really like the composition. Great colors and lightling. But you can add a little more detail. It would be much more beautiful. A few more holes on the dark side maybe, or a boat. But still a very good work, well done.
Thanks! I think I’ll agree on putting a boat there. 
I think the waves look a little too rough for piece called calm. I think if you smooth out the waves, add that boat, this would be really neat. And very fitting to the title. I love the sunset.