When navigating a vessel, which sound signal indicates that you are backing up?

The sound signal that indicates a vessel is backing up is represented by three short blasts of the horn. This is standardized under the International Regulations for Preventing Collisions at Sea (COLREGs), which outlines the use of sound signals to communicate the actions of a vessel to others in the vicinity. When a vessel is engaged in backing up, it signals its intent clearly through this specific sound pattern, alerting nearby vessels to its maneuver and helping to prevent potential collisions.

In contrast, other sound signals serve different purposes, such as one short blast, which indicates the intention to pass to the starboard side of another vessel, and two short blasts, which signify passing on the port side. A prolonged blast typically serves as a warning signal, indicating that the vessel is constrained by its draft or has limited maneuverability. Understanding these signals is crucial for safe navigation and effective communication between vessels on the water.