What must overtaking vessels do to facilitate safe passing in a narrow channel?

Overtaking vessels are required to sound the appropriate signals as prescribed to facilitate safe passing in a narrow channel. This is crucial for ensuring that both the overtaking vessel and the vessel being overtaken are aware of each other's intentions. The sound signals help convey information concerning the overtaking maneuver, especially in situations where visibility may be limited or where vessels may not be able to visually identify one another's actions clearly.

The use of appropriate sound signals is integral to adhering to the COLREGs, which emphasize the importance of communication between vessels to prevent collisions. By signaling, overtaking vessels can indicate their intentions to overtake and the actions they will take, allowing the other vessel to respond accordingly and maintain safe navigation through the narrow channel.

In contrast, relying solely on non-verbal communication would not ensure the same level of clarity and understanding necessary for safe navigation. Attempting to pass quickly without communication increases the risk of misunderstandings and potential collisions. While using radar can be an important tool for navigation and collision avoidance, it does not replace the need for active communication through sound signals when overtaking in narrow channels.