In what scenario should you consider reducing speed besides restricted visibility and poor weather?

• A. Low traffic situations with long overtaking distances.
• B. In all cases, regardless of traffic or weather.
• C. Only when within harbor entrances.
• D. High traffic situations to allow more time to react.

Answer: (D)

In heavy traffic, reducing speed is prudent because it gives you more time to observe, assess other vessels’ actions, and react to sudden changes. When many vessels are sharing the same waterways, maneuvering space is limited and the actions of others can be unpredictable; a slower speed increases your ability to maintain a safe distance, reduces stopping distance, and helps you comply with the safe-speed guidance under the COLREGs.

Other scenarios described don’t require slowing as a necessity. If traffic is light and there’s plenty of distance for overtaking, maintaining a safe speed appropriate to conditions is usually fine. Harbor entrances aren’t the only times to adjust speed, and slowing all the time, regardless of conditions, isn’t appropriate when conditions are clear and traffic is sparse.