Under what circumstance should a vessel not cross a narrow channel?

A vessel should not cross a narrow channel if it would impede another vessel's passage. This principle is grounded in the Navigation Rules, which prioritize safe and efficient navigation for all vessels. Narrow channels often have limited space, and vessels navigating within such areas have reduced maneuverability. If a vessel were to enter the channel and obstruct another vessel's safe passage, it could lead to dangerous situations, including collisions or grounding.

Maintaining the right of way for the vessels that are already navigating the channel ensures the safety of all vessels involved. In contrast, factors such as vessel length, whether cargo is being carried, or visibility conditions, while important for navigation, do not take precedence over the obligation to avoid obstructing other vessels within a narrow channel. The focus here is really on the interaction between vessels and the importance of adhering to established navigational protocols to prevent accidents.