Very nice work!
Great atmospherices and lighting
I only have 2 suggestions now at the moment + one minor:
The specularity is a bit disturbing IMO, I'd reduce the reflectivity and increase the roughness to soften en spread it out a bit more. I'd certainly reduce it, it's too strong for these kind of lighting conditions I think.
The wave scales of the water are rather large. The atmosphere of the image almost "requires" dead calm water, at least with very tiny waves.
Minor suggestion is to increase the atmo-samples in your final render to remove more grain (you can see it in the atmo itself a bit, but mostly in the objects).
I guess you used something like 100 samples already?
Keep up the great work!
Cheers,
Martin