Today I added a simplistic water buoyancy mechanic to Tutel. For now only objects with a specific script will float, while everything else sinks - which for now is all that's needed.
Next, I need to add to the character controller so when in water they can swim around.
I also messed around more with my water shader graph - I still cannot figure out an easy way for the top surface to stretch the sides (rather than just be detach and float), but currently, it's not a priority and I might end up going with a 3rd party shader anyway.