I’ve run into this problem, where my Water Plane is producing really aggressive Shadow/light glitches with my directional light.
Here you can see how it looks:
Summary
This only happens with Translucent Materials. It also disapperas when I go into my directional light and uncheck “affect translucent lighting” but that’s no option for me.
So I’ve fiddeled around with the directional Lights settings because i thought it could have something to do with cascaded shadow maps or distance field shadows but turn’s out that makes no difference.