If a vessel is overtaking another, what signal is used to indicate intent to overtake on the starboard side?

The signal used to indicate the intent to overtake another vessel on the starboard side is two prolonged blasts followed by one short blast. This specific signal is part of the sound signals outlined in the COLREGs and is used in situations where vessels are navigating in close quarters, particularly in narrow channels or congested waters.

When a vessel intends to overtake another, it must communicate its intentions clearly to avoid confusion and ensure safety on the water. The two prolonged blasts signify a warning that the overtaking vessel is maneuvering, while the single short blast clarifies the side on which the overtaking will occur—specifically the starboard side, meaning the overtaken vessel should be aware that it may need to keep to port or adjust its course accordingly.

This type of signaling is crucial for maintaining a mutual understanding between vessels, especially when visibility is limited or when other factors may impede clear communication. By following these established sound signals, vessels enhance navigation safety and help prevent potential collisions or misunderstandings during overtaking maneuvers.