Discuss the stability of (a) a submerged and (b) a floating body whose center of gravity is above the center of buoyancy.
According to archimedes principle
The vertical buoyant force experienced by a body immersed in a fluid is equal to the weight of the fluid displaced.
A floating body displaces its own weight of the fluid.
If the center of buoyancy is above the center of gravity then the body is stable. If you tip it, it will tend to right itself. This is because of the torque created by the weight acting down and the buoyant force acting up.