Still adjusting values of the shaddow part

I sensed the shadow part is not dark enough to compare to the lighter part, at the same time the shapes were not right. I still keep pushing the values. I started with the center. The island of rocks in the center is the good place to start.Other part would become relative to the center part.

I also darkened the white water splash not to stand out too much. The entire view was in shadow anyway.