Stability is determined by the relationship of which two points?

Stability in a marine context primarily relates to the relationship between the center of gravity and the center of buoyancy. The center of gravity is the point at which the weight of the vessel is concentrated, while the center of buoyancy is the point at which the buoyant force acts, which is influenced by the underwater volume of the vessel's hull.

When a vessel is tilted or heeled, these two points shift relative to each other, impacting the vessel's stability. If the center of gravity is above the center of buoyancy, the vessel will tend to return to an upright position if disturbed. Conversely, if the center of gravity is too high, it can lead to instability, making the vessel more susceptible to capsizing.

The other options, while related to vessel performance and characteristics, do not specifically address the fundamental relationship that defines stability. For instance, the waterline and metacenter have implications for stability, but they relate to buoyancy characteristics rather than the direct interaction of gravity points. Similarly, the cargo hold and main deck, or draft and trim, involve loading and distribution factors but do not directly define the vessel's stability in the same way that the center of gravity and center of buoyancy do.