When should a stand-on vessel change course?

A stand-on vessel should change course when it becomes apparent that action by the give-way vessel cannot avoid a collision. This principle is crucial to maritime navigation rules, which dictate that the stand-on vessel maintains its course and speed in most situations to help avoid confusion and ensure predictability.

However, if it's clear that the give-way vessel (the vessel that is required to take action to avoid a collision) is not able to take appropriate action—whether due to a lack of maneuverability, poor visibility, or any other reason related to the conditions of navigation—then the stand-on vessel must take action to avoid a collision. This action could involve changing course or adjusting speed as necessary to ensure safety.

Maintaining awareness of the surrounding vessels and being ready to act if the situation deteriorates is essential for safe navigation. Adhering to this principle helps prevent accidents and promotes safety on the water, respecting the responsibilities assigned to each type of vessel under the rules.