Below is the same image after applying the Rule of Thirds. I was really playing about with on what side to position the boat. At first I quite liked its composition on the left of the frame but although the image had much more energy, on the right side of these two buildings stands a very obvious toilet block and the grey of concrete made the image also quite boring. I like this composition very much though. This image has an energetic quality and the boat belongs, if that makes sense. It also looks like it could be put into the water at any moment. The red of the roof stands out between the different shades of blue of the sea, the sky and the little door.
Lastly, following Matt's suggestion to crop the boat even more: