I know that you can increase the size of the WaterMeshActor to render more water, but the size of the WaterBodyOcean volume is still constrained. You can technically extend the island as far as you want, but any water past the constraint of the WaterBodyOcean won’t render the underwater effect when the camera is underwater. I haven’t been able to find anything in the settings to increase the size, and scaling the actor doesn’t work. Is there any way to make the size of the WaterBodyOcean volume larger, or is it stuck at its current size. If there is no way to make it bigger, is this a feature that will be added in the future?
Yep, I finally found the answer. For anyone who is looking to expand the underwater post processing size here is the answer New 4.26 water questions - #16 by kernelkiller. Select your WaterBodyOcean instance go to Collision and change the X,Y of Collision Extents. Now you can have an infinite ocean.
Also to increase surface size. Select your WaterMeshactor > under heading Mesh > increase decrease x,y of Extent in Tiles. By increasing Extent in Tiles and Collision Extents you can make an infinite ocean.