BOTH INTERNATIONAL & INLAND You are crossing a narrow channel in a small motorboat. You sight a tankship off your port bow coming up the channel. Which statement is TRUE?

Correct Answer: Option D — You cannot impede the safe passage of the tankship.

Rule 9(b) explicitly prohibits any vessel from impeding the passage of a vessel that can safely navigate only within a narrow channel. Regardless of the crossing situation or the size of the vessels involved, the requirement to not impede the deep-draft vessel takes precedence over standard steering rules.