Hi, I'm working on simulating objects behavior underwater. So far here's what I have:

Buoyancy. Upward force that's equal to the displaced water. This would determine if objects float or not. I have no idea yet on how to implement this but I'll figure it out in the next few days. It could be as complex as having different fields for each object or as simple as an flipped gravity.

Pressure? I still haven't got a solid grasp on this idea. So far, I know pressure is a force that acts on the object to all directions. That force magnitude is greater in depth.

Viscous is similar to friction or a force that resist movement.

I have yet to read a material that mentions movement of water in underwater. Is it as simple as wind?

Here's a run down
Gravity
Buoyancy - upward force/upward gravity
Pressure - clueless
Viscous - Drag/Turbulence/Noise field

Thank you for your help.