What action should a vessel take when it hears the sound signal of another vessel indicating it is altering course?

When a vessel hears a sound signal from another vessel indicating it is altering course, it is crucial for the crew to assess the situation and adjust their own course accordingly. This action is based on the principles of safe navigation and collision avoidance outlined in the International Regulations for Preventing Collisions at Sea (COLREGs).

When one vessel signals that it is changing course, the other vessel must determine the potential implications of this change on their own navigation. Assessing the situation helps in understanding the relative movements and intentions of both vessels, which is vital for maintaining safety at sea.

Adjusting course may involve altering speed or direction to ensure that a safe distance is maintained between vessels, thus preventing potential collisions. The situation should be evaluated based on factors such as visibility, the proximity of the other vessel, and any other navigational hazards that may exist.

In contrast, actions such as continuing on the current course or maintaining speed and position without assessing the surrounding context can lead to dangerous situations. Signaling back with the same sound does not provide meaningful information and could potentially lead to confusion. Therefore, the correct response is to evaluate the situation and make necessary adjustments to navigate safely.