I like the water and the light reflection on the water - that's cool. I do wish the composition had more room at the top for the lighthouse. It's tight, needs another 20-40 pixels at least IMO. Sky seems a little grainy also... All JMO of course. :-) Good luck in the challenge.
I think this would have benefited from a bit more contrast, perhaps also a B&W. It's also a shame you couldn't get more of the light coming from the lighthouse. I love the concept though