What does the stability curve represent?

The stability curve represents the vessel's righting arm at different angles of heel. The righting arm is a critical factor in determining a vessel's stability; it is the horizontal distance between the center of gravity and the center of buoyancy when a vessel is heeled. As the angle of heel increases, the righting arm changes, reflecting how effectively the vessel can return to an upright position when tilted.

Understanding the stability curve is essential for evaluating how a vessel will behave in various sea conditions and how far it can lean before it may capsize. This information is crucial for safe vessel operation and design, ensuring that the ship remains stable under different loading conditions and during maneuvers.

The other options, while relevant to various aspects of a vessel's performance, do not pertain to the stability curve specifically, which focuses solely on the relationship between heel angle and righting moment.