How does an increase in beam typically affect a vessel's GZ curve?

An increase in beam enhances the vessel's stability characteristics, which directly impacts the GZ curve. The curve represents the righting lever (GZ) as a function of the angle of heel, and the area under this curve is indicative of dynamic stability.

When the beam increases, it generally leads to an increase in the vertical distance between the center of gravity (G) and the center of buoyancy (B), which results in a higher metacentric height (GM). A higher GM indicates that the vessel will have a greater righting moment in response to heel, contributing positively to dynamic stability.

As a consequence of the increased beam, both the peak GZ (the maximum righting lever) and the overall area of the GZ curve are likely to increase. This means the vessel is more stable and can right itself from larger angles of heel. The increased beam can also positively affect the angle of vanishing stability, extending the range over which the vessel maintains dynamic stability.

Understanding these principles highlights the importance of beam in designing vessels for optimal stability, ensuring they can operate safely under various conditions at sea.