1. Focus.
2. All the black dots. 1 is minimal.
3. Too much information, leads to lack of focus.
4. The colour, the boat should be in contrast.
5. It is not under sail. I know, WHAT? A sail boat in its minimal state, should be under sail.
There is a ridiculous amount of noise in this image. If you really had no choice about the grain, you could have used a softer focus to make it look more artistic.
I like the shillouette of the sailboat on the water. However, I think that a little tighter view of the boat might give us some more detail, but would still fit within the parameters of the challenge.