How to Apply Swamp Algae Layer to Water?

i seem to remember there is an algae texture/mesh some place in there …
I remember adding it to my map, a long time ago, and it looked like poo. Just didnt feel right.
Now, thinking back to playing ark, i do remember being able to show/hide algae layer when going above or below the water line, and, timed just right, you can see just that layer (as you know, there is a “line” where the postprocess layers dont get shown at all, seems kinda fixed in the latest Arks tho).