Centre of Bouyancy

[mattihase]

One thing I noticed would be kinda handy while working on vessels for the recent seaplane weekly challenge would be a way to estimate how a vessel will lie in the water. One thing that'd be super helpful is to have an indication of a craft's centre of bouyancy at current orientation (ocean configurable) in the OAB, as well as a waterline for working out how a craft would lie in the water without having to constantly relaunch it to test different positionings.

This'd also be handy for boats, and probably stuff along the lines of seadragon.

I know these are mostly niche things to build in the game but it'd still be nice to have some more support for them, to go along with already having the dedicated boat launch station.