Make an Endless ocean?

I have a water prefab that moves and foams. I could make the water object larger to cover a large game world, but I don't want to make it so big that the game would lag. Is there a way to make it appear to be everywhere, like an endless ocean, while only covering a small portion of game world?

Using the Azure sky Dynamic Skybox and the Low Poly Underwater Pack assets. I didn't do anything fancy with the camera yet as I am not entirely sure what to do with it yet. However, I would like it to view the entire world at the beginning, sort of like Sims or Fortnite, with water all around it. Also I am planning on using either a top-down or third camera view for game play.