Which type of vessel may not impede another vessel navigating in a narrow channel?

A vessel of less than 20 meters in length is often allowed to navigate more freely in narrow channels and is typically not considered a hindrance to larger vessels that may require more space to maneuver. In the context of COLREGs, smaller vessels usually have less maneuverability due to their dimensions, but their potential to impede navigation is also based on the size and operational characteristics of larger vessels in the same waterway.

The regulations prioritize the safety and efficiency of navigation, particularly in narrow channels. The rules indicate that larger vessels must be able to navigate safely without being impeded by smaller craft. Therefore, a vessel of less than 20 meters in length is generally expected to keep clear of larger vessels to allow for safe passage.

In contrast, the other vessel types listed—like those over 20 meters, sailing vessels with limited maneuverability, or fishing vessels—are often constrained in their ability to maneuver due to their size or operational requirements, which makes it essential for them to adhere to the navigation rules in a way that acknowledges their impact on traffic flow in narrow channels.