What is the primary measure of a vessel's ability to resist capsizing?

The primary measure of a vessel's ability to resist capsizing is metacentric height. This concept is fundamental in stability theory because it directly relates to how a ship responds to tilting or heeling. Metacentric height is the vertical distance between the center of gravity (G) and the metacenter (M), which is the point where the buoyant force acts when the vessel is tilted.

A larger metacentric height indicates a greater resistance to heeling and capsizing, as it enhances the lever arm that assists in restoring the vessel's upright position when it is tilted. When a ship heels, it creates a righting moment, and the metacentric height plays a crucial role in determining the size of this moment. Therefore, understanding and calculating the metacentric height is essential for assessing a vessel's stability performance and safety at sea, especially in rough conditions.

While center of gravity, righting arm, and cargo distribution are all important factors that influence overall stability, they do not directly quantify the vessel's inherent ability to resist capsizing in the way that metacentric height does.