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

The requirement for overtaking vessels to sound the appropriate signals as prescribed is rooted in the need for clear communication to ensure safety during the maneuver. In narrow channels, the risk of collision increases due to limited space and the presence of other vessels. By using the prescribed sound signals, the overtaking vessel can alert the vessel being overtaken of their intentions, facilitating a safer passing process. This communication is essential to maintain situational awareness for all vessels involved and to allow for necessary adjustments to their navigation as they approach each other.

Sound signals play a crucial role in maritime communication, especially when visibility might be reduced or when vessels are not in direct sight of one another. They allow both vessels to have a mutual understanding of the actions being taken, thereby minimizing the likelihood of misunderstandings that could lead to dangerous situations.

The other options do not align with the established COLREGs. Non-verbal communication, while helpful among crew members, is not standardized for interactions between vessels. Attempting to pass quickly without any form of communication disregards the principle of safe navigation and could lead to collisions. Depending solely on radar to determine distances without clear communication does not account for human factors and the need for collaborative awareness in a narrow channel situation.