STEP ONE:
Blocked out environments and added the sky and ocean backgrounds in.  

STEP TWO:
Added textures throuch painting and clipping masks. Corrected shadow and picked the location and direction of light source.  

STEP THREE:
Created more dimension through rock formations and fog. Applied more shading and darkened scene.

STEP FOUR:
Placed ship and painted on light, reflections, and shadows. Adjusted fog, water, and clouds to unify the painting.   

Finished scene. Done is Photoshop