ANGLE OF LOLL A ship which is slightly unstable in the upright condition may become stable as it heels over. The GZ curve for such a case is shown:
In calm conditions, the ship will float at an angle equal to that at which GZ becomes positive. This is the angle of loll. The ship will loll to port or starboard depending on how she arrived at the initial condition. A small moment applied to bring it upright will cause her to “flop” suddenly to a similar angle on the other side. An experienced master will recognise from the motion of the ship when she exhibits this characteristic and can decide what action needs to be taken.