Which action best indicates a risk of collision based on bearing and range?

• A. Accelerate to pass immediately
• B. Slow down and turn away
• C. Continuously listen for horn signals only
• D. Observe whether the bearing to the other vessel does not change and the range decreases

Answer: (C)

The main idea here is how to tell if two boats are on a collision course by looking at relative motion. If the bearing to the other vessel stays fixed while the distance between you both gets smaller, you’re on a collision course. That pattern—unchanging direction with decreasing range—is the clearest diagnostic sign that a collision risk exists, so noticing it means you should take early action to avoid a crash.

Listening for horn signals alone doesn’t reveal how the vessels are moving relative to each other, so it doesn’t reliably indicate collision risk. Focusing on changing speed or course to alter the bearing and increase the distance is the practical next step once you detect that fixed bearing with closing range.