What is a "cross curves of stability"?

A "cross curves of stability" refers to graphs that illustrate the stability characteristics of a vessel at varying angles of heel. These curves provide vital information about a ship's righting moment, the metacentric height, and the overall stability for different loading conditions. By analyzing these curves, mariners can determine how the ship will behave when it experiences tilting due to external forces such as wind or waves.

This information is crucial for ensuring the vessel remains stable and seaworthy throughout its operation, particularly when maneuvering or encountering rough seas. Understanding how the righting lever changes with heel angles helps in making informed decisions about loading and ballasting to maintain optimal stability.