Why might a ship with a narrow beam have stability concerns?

A ship with a narrow beam has stability concerns primarily because a narrower beam contributes to a higher susceptibility to capsizing, especially in rough seas. Stability in maritime terms is influenced significantly by the beam (the width of the ship). A wider beam generally provides a larger righting arm, which enhances the vessel's ability to return to an upright position after being heeled over by wind or waves.

In contrast, a ship with a narrow beam has a smaller righting arm, which can result in a lower metacentric height (GM). This situation diminishes the effectiveness of the ship's inherent stability, making it easier for external forces, such as large waves or strong winds, to cause the vessel to heel to a critical angle where capsizing can occur.

While increased cargo capacity, fuel requirements, and speed may relate to other design aspects of ships, they do not directly connect to stability as the narrow beam does. The focus on stability highlights how crucial it is for a vessel's design to balance operational efficiency with safety considerations.