In a narrow channel, you are in an 18-meter tug and sight a loaded tankship off your port bow coming up the channel. Which statement is correct?

• A. You may accelerate to pass ahead of the tankship.
• B. You cannot impede the safe passage of the tankship.
• C. You should immediately reverse and back out.
• D. You should stop and wait for the tankship to pass.

Answer: (B)

In a narrow channel, you must not block or impede another vessel’s safe passage, especially a large, heavily loaded ship that has limited ability to maneuver. Here, a loaded tankship is coming up the channel from your port bow. That vessel needs the space to pass, and your priority is to keep clear and not obstruct its course. Accelerating to try to pass ahead would risk squeezing into a confined space and forcing the tanker to alter course or slow abruptly, which is unsafe. Reversing or stopping to wait can be unsafe or unnecessary if there is a safe way to let the tanker pass without creating a blockage, but the fundamental rule is you cannot impede the tankship’s safe passage.