Which factor does NOT contribute to dynamic stability?

Dynamic stability refers to a vessel's ability to maintain its upright position and resist rolling when subjected to external forces or disturbances, which is crucial for safe navigation and operation. Among the factors considered, conditions while at anchor do not impact dynamic stability since the vessel is not in motion and is at rest.

The righting arm curve, which illustrates the vessel's righting moment against heeling angle, directly relates to how effectively it can recover from heeling under dynamic conditions. External disturbances, such as waves or wind, are fundamental in testing a vessel's dynamic stability as they generate heeling moments. Additionally, vessel design features, like the shape of the hull and the placement of weight, play a significant role in determining how a vessel responds to dynamic forces.

Thus, it is the conditions while anchored that do not influence dynamic stability as they occur when the vessel is stationary, and therefore are not factors in assessing how well a vessel maintains stability when in motion or under external influence.