How is a vessel deemed to be overtaking another vessel?

A vessel is deemed to be overtaking another vessel when it comes from an angle greater than 22.5 degrees abaft her beam. This definition is critical in the context of the COLREGs, specifically Rule 13, which addresses overtaking situations. According to the regulations, if a vessel approaches another vessel from behind or at an angle that is more than 22.5 degrees behind her beam, it is considered to be overtaking.

This rule is designed to provide clarity on navigation rights and the responsibilities of vessels in overtaking scenarios. When a vessel meets this criterion, it must give way to the vessel being overtaken. This ensures safety at sea by clearly defining who has the responsibility to maneuver.

To understand why other options do not fit this definition, a vessel approaching directly ahead does not fall into the overtaking category because it is not coming from behind the target vessel. Additionally, an approach from less than 22.5 degrees abaft the beam indicates a crossing situation or that the vessel is on a more direct course relative to the beam, thus not overtaking. Lastly, the speed of a vessel does not determine the overtaking status; it is purely based on the relative angle of approach to another vessel.