Changes

The righting moment (restoring force) is GZ multiplied by displacement (D). The longer the righting arm and/or the heavier the displacement, the greater the restoring forces.

As the boat exceeds its range of initial stability, and enters the zone of ultimate stability, the restoring force begins to decrease. This happens due to the changing shape of the immersed hull. As it continues to heel, the CB shifts inboard and the righting moment becomes less and less just when the boat needs more and more to restore it to upright. The boat becomes increasingly unstable. When the CB moves to the opposite side of the CG, the righting moment becomes an upsetting moment. When the boat reaches its Angle of Vanishing Stability it capsizes.