Wtf is wrong with this texture?

[Statyk]

Not sure if this will work, but perhaps its because the water is trying to render the void. Try surrounding the outside area with black technical planes. (just an experiment)

Or perhaps open the material in the Material Editor and uncheck World reflection, then save as a new material.

Another tip would be to remove cubemaps on both of those transparent materials. It makes the material "emissive" in dark areas.