This is an idea posted as an expansion of this thread:
3rd party developers need a way to be able to apply water masking in our sceneries. In an attempt to get this a bit higher up the board, I'm taking the initiative to create this thread so that it may be voted on.
Now, it has been mentioned that this method isn't as straight forward due to "technical implications", however could something such as a poly only displaying the water effects be used (where the base color would be transparent, or very minimal, allowing the below imagery to show)? The edge could have an adjustable feather that could serve as a gradient, blending with the color of the surrounding default water.
Not sure how feasible this is, but maybe it would be a simpler approach than going the CGL route?