Hey there @RoyalKirin! Welcome to the community! After a certain distance from the center, the water body actually turns into a lower resolution/imposter of itself for performance purposes, so you usually do see there the seams in editor, but if your gameplay is confined to the island it’s usually quite hard to pick out!
However the artifacting where the chunks of land are still poking through near the edges is a bit of a problem. This generally occurs if the water volume itself doesn’t cover the entirety of the landmass, or if the curve itself is adjusted too close or too far.