Looks really good Dune. Can I make a slight suggestion? The wet rock surface layer, could you break the reflection up with two instance of reflection, controlled by one PF, inverting the output to the other. Maybe putting a little more fuzziness on the altitude. The idea being getting two tones of wet, one just splashed, the other where the water has run away slightly, just so your rocks don't look as if they are made of glass. OR, give your kelp a slightly less reflection strength.
It's a great scene, and that would be my only suggestion.
Cheers
Jon