I would like to create a COSMOS enviroment detailing the specifics of water - and how it reacts to a body in that water. Is it possible to simply identify all of the water's forces, or is there a package that more easily accomplishes my task?
Cosmos will allow you to apply non-uniform pressure, Check the tutorial and search for "hydrostatic."
You will need to supply the number for density for the fluid you are using. For water there are slightly different numbers for density of freash water versus sea water.
good luck-
-MB