Which action is prohibited for vessels in a narrow channel?

In the context of navigation rules, particularly in narrow channels, anchoring a vessel is generally prohibited unless absolutely necessary. This regulation is in place to ensure the safety and efficiency of navigation in restricted waters where space is limited, and maneuverability is critical. Anchoring can obstruct the passage of other vessels that need to navigate through the channel, increasing the risk of collisions and dangerous situations.

Navigating these channels often involves the passage of large ships, and anchoring can create hazards not only for the vessel at anchor but also for those who might be unable to maneuver around it. Therefore, vessels are encouraged to maintain their movements through these areas unless there is a compelling reason to stop, such as emergency situations or equipment failure.

In contrast, crossing from one side of the channel to the other can be permitted depending on the circumstances and the navigation situation, though it should be done with caution and appropriate signaling. Maintaining a sailing speed is typically necessary to keep control of the vessel, and using lights and horns correctly is crucial for safe navigation in these areas.