BOTH INTERNATIONAL & INLAND Which vessel is NOT to impede the passage of a vessel which can only navigate safely within a narrow channel?

Correct Answer: Option D — All of the above

Rule 9(b) prohibits any sailing vessel, any vessel engaged in fishing, or any vessel less than 20 meters in length from impeding the passage of a vessel that can safely navigate only within a narrow channel. These vessels must prioritize the safety of deep-draft or restricted vessels.