When should a vessel agree to be overtaken according to signal rules?

A vessel should agree to be overtaken upon receiving the overtaking signal because this is a crucial part of the navigation rules established by the COLREGs. When a vessel signals its intention to overtake another, the overtaken vessel is expected to acknowledge this signal and take appropriate measures to assist the overtaking process. This includes maintaining a steady course and speed, which helps ensure the safety and efficiency of the maneuver.

The process for overtaking is designed to reduce the risk of collisions and improve the flow of maritime traffic. By agreeing to be overtaken after receiving the signal, the vessels involved are following the established protocols that govern their actions on the water, contributing to safer navigation practices.

In contexts such as being at anchor, in restricted waters, or in international waters, while each presents specific navigational challenges and requirements, they do not directly pertain to the agreement or acknowledgment of overtaking signals. The key factor in this situation is the communication and recognition of the overtaking intent, solidifying the importance of adhering to the signaling protocol outlined in the COLREGs.