A vessel shall be deemed to be overtaking when she is in such a position, with reference to the vessel she is approaching, that she can see at night __________.

A vessel is considered to be overtaking another when it is in a position such that the operator can see only the stern light of the other vessel at night. This situation indicates that the overtaking vessel is behind and to the side of the other vessel. Under the International Regulations for Preventing Collisions at Sea (COLREGs), if one vessel can only see the stern light of another, this confirms that the overtaking vessel is not directly facing the other vessel, but rather is approaching from the rear.

In terms of navigation and safety, being aware of this position is critical for determining the appropriate actions to take while maintaining a safe distance and avoiding collision. Other combinations of lights, such as seeing both the stern light and a sidelight or just a sidelight, might indicate a different navigational relationship, which would not fall into the overtaking category as defined. This defined understanding helps operators make informed decisions on how to proceed when encountering other vessels in various navigational scenarios.