In this video, learn how to apply a buoyancy force to rigidbody's that sync to vertex shaders.
Github Project: https://github.com/CBerry22/Buoyancy-in-Godot-4
If you want to know how to make the water shader itself, check out this amazing video by @stayathomedev
https://www.youtube.com/watch?v=7L6ZUYj1hs8