English: Illustration of the stability of bottom-heavy (left) and top-heavy (right) ships with respect to the positions of their centers of buoyancy (CB) and gravity (CG). It is to be noted that the CG being located above CB is not the cause of instability. The increasing height of CG decreases stability. CB will move as a vessel rolls, CB appears to pendulum below a point named the metacenter (M) If CG is higher than M then the vessel is unstable. As CB will apply an upward force and CG a downward, so when stable CG is inboard of CB during a roll and a righting arm will lever the vessel upright (left) and when unstable CG is outboard CB and will lever the vessel over (right)