Which vessels may not impede on another in a narrow channel?

The correct answer indicates that vessels less than 20 meters in length, as well as sailing and fishing vessels, may not impede another vessel's navigation in a narrow channel. This is based on the navigational rules established by the International Regulations for Preventing Collisions at Sea (COLREGs).

In narrow channels, it is expected that larger, more maneuverable vessels maintain the right to navigate freely. As smaller vessels, those under 20 meters in length, along with sailing and fishing vessels, can be more limited in their maneuverability or may be engaged in activities that require them to operate close to the channel margin. Consequently, they are expected to avoid impeding larger vessels’ passage.

This rule is designed to ensure safety in navigation, especially in constricted waterways where the maneuvering space is limited, and the risks of collision are heightened. Thus, the understanding is that smaller and specialized craft must yield to larger vessels wherever possible to prevent unsafe situations in these environments.

The other options incorrectly imply that different criteria or vessel classifications do not adequately account for the nuances of navigation in these settings, or they misrepresent the obligations of specific vessel sizes regarding channel usage.