C&C: I think the ship needs DIRT! Throw some PF's over the parts, either into the color input of the defaults, or as a 0.5 coverage surface shader under it, blended by a PF. Especially the wood should be stained, greyed and dark.
The waves I would make a little rougher, and perhaps use more patchiness. And how did you get the foam behind the ship? If by projected image map shader from a camera at the ship's location, the white is cast very straight and doesn't really follow the waves. If so, you might be better of using a painted shader (Y projection) or a soft triangle (SimpleSS) for the whole wake, and then a ridged and warped PF, rotated into the right direction by a transform shader.
I very much like the cloud, by the way.
