When positive stability exists, what does GZ represent?

When positive stability exists, GZ represents the righting arm. The righting arm is a crucial concept in the study of stability in vessels. It is the horizontal distance between the center of gravity (G) and the center of buoyancy (Z) when a ship is tilted or heeled over. This distance is what generates the righting moment that tends to return the vessel to an upright position.

In the context of positive stability, a larger righting arm indicates a greater ability of the vessel to return to an upright position after being tilted. This is essential for maintaining stability in a ship, especially in rough seas or during maneuvers. Therefore, GZ is a key measurement in determining how stable a vessel is and reflects its ability to recover from heeling moments caused by external forces such as waves or wind.

Understanding the significance of the righting arm helps mariners to assess the safety and seaworthiness of a vessel, making this concept integral to marine operations and vessel design.