What is centre of buoyancy?

The center of buoyancy of an object is located at the point that would be the center of mass of the displaced fluid that would occupy the volume that is actually occupied by the buoyed object.

In the same way that gravity can be thought of as pulling on a compact object by acting on its center of mass, the buoyant force can be thought of as acting on a compact object (a particle) at that particle's center of buoyancy.

An object whose center of mass is lower than its center of buoyancy will float stably, while an object whose center of mass is higher than its center of buoyancy will tend to be unstable and have a tendency to flip over in the fluid that is buoying it up.

The centre of buoyancy is the centre of gravity of the displaced fluid.