4-27 Can't remove some water noise within WaterBodyOcean spline

Hello everyone.
So, i can’t remove this water noise…
How i get this:

  • created project and and connected the plugin Water;
  • created 15 landscapes with World Composition (created 15 levels);
  • imported a heightmap into a single layer that was;
  • drag’n drop WaterBodyOcean and set up all spline’s point around main island

Вy itself WaterbodyOcean does not really affect the landscape (as i wanted).
But this water noise (i don’t know how to call it) spoils the whole result.
Has anyone come across such a problem?
Thanks in advance for the answers =)
P.S.: Sorry if my english is bad =)
P.P.S.: Please, give a detailed answer if you can - I’m new at unreal engine