What does the term 'not under command' mean?

The term 'not under command' refers to a vessel that is unable to maneuver as required by the Rules of the Road due to exceptional circumstances, such as a mechanical failure, loss of propulsive power, or other reasons that hinder its ability to steer or adjust its position. This designation is crucial in maritime navigation because it alerts other vessels of the situation, allowing them to take appropriate actions to avoid collision or navigate safely in the vicinity.

When a vessel is classified as 'not under command,' it must display the appropriate signals, such as two all-around red lights at night or a day shape consisting of two black balls. This ensures other mariners are informed that the vessel cannot comply with standard navigational protocols, necessitating heightened caution.

Understanding this term is essential for maintaining safety and adhering to the COLREGs, as it plays a key role in preventing accidents at sea. The other definitions provided do not accurately convey the conditions required for a vessel to be considered 'not under command,' as they pertain to different situations or statuses.