The documentation
River Water Bodies act as connections between other water bodies. At the points where lakes and oceans intersect a river, you can use a transitional material to automatically blend them together seamlessly. Water Body Actors in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer Community
I have setup a river and ocean in 5.5 and it is not seamlessly blended
The river materials …
When zooming closer the transition looks better
