I think it is a very decent composition. Post processing wise I would manipulate it a bit, repositioning the boat a bit more lower and to the left. Whether that is cheating, I leave that up to you. Photography is something creating a world of make believe and there is nothing against it if you leave the viewer with a 'wow' moment, without giving the impression that he/she is lookin at something that is obviously fake.
Perhaps check the horizon as it looks slightly slanted towards the right, furthermore I believe there are some dust spots (smudges) on the horizon line that could be easily repaired. All items mentioned are post processing, so does not really relate to the initial shot itself. Hope this helps, cheers!