I used Image based Color with an Underwater Picture to get some different nice blue colors. Then i used The Ruffle Brush to create the rockformations and different colors of the water. Another layer was added for the sinking ship with a plain black base and the hay brush by ben-o.
The different shadfes of grey on the rocks turned out too bright so i used the cloud brush by easle-darkpaws to cover that up. That part is probably the most sloppy but it leaves room for improvement i guess. I hope you like it and I am looking forward to your feedback!
Since i could't sleep anyways i decided to smooth things out a little more.