What does "SAG" refer to in terms of vessel stability?

The term "SAG" in relation to vessel stability refers to the position of the center of gravity in transverse stability. Understanding this concept is crucial as the stability of a vessel is significantly affected by where its center of gravity is located. When the center of gravity is lower, the vessel has increased stability because it has a greater righting moment, allowing it to return to an upright position after being tilted. Conversely, if the center of gravity is higher, it may lead to a less stable condition, making the vessel more prone to rolling and capsizing.

In assessing vessel stability, it's important to also consider how the distribution of weight affects the center of gravity. Thus, managing the position of the center of gravity is critical for ensuring the vessel remains stable under various loading conditions and during different sea states.