When an unstable vessel heels over towards a progressively increasing angle of heel, at a certain angle of heel, the centre of buoyancy (B) may fall vertically below the centre of gravity (G). When this occurs, the vessel goes to neutral equilibrium, and the angle of heel at which it happens is called angle of loll.
Although a vessel at angle of loll does display features of stable equilibrium, this is a dangerous situation and rapid remedial action is required to prevent the vessel from capsizing.

Angle off loll is often caused by the influence of a large free surface or the loss of stability due to damaged compartments.