The buoyancy of an object determines how fast an object sinks, or if that object is capable of floating. Archimedes principle is used to calculate the buoyancy force placed on an object by relating an object’s submerged volume to the fluids specific weight. Refer to equation 1 to determine the buoyancy force.
(Eq 1) $F_B=γV$
FB = Buoyancy Force
γ = Specific Density
V = Submerged Volume
Stability of a Floating Object
There is a point on an object where the buoyancy force acts, and this can be used to determine an object’s stability while it is floating in the fluid. If the center of gravity is below the buoyancy force then the object is stable, if it is above the center of gravity then the object has an unstable equilibrium.
If the object is wide enough however an unstable equilibrium can become stable since the buoyancy force will shift as the object rocks back and forth counteracting the instability.