How can I make a water volume/lake?

I cant answer your question, but have more to add to it I suppose.

I’d like to create reactive water. Something that looks like an ocean, but also is reactive to objects passing over and through it. GTA ocean water to put is short. I’ve tried planes with textures. I’ve tried cube meshes with an insane poly count on the top surface triangulated as nicely as I could. Still, all I get is a good poly ripple effect with no physics. How can I make that poly reactive?