Which of the following is not a factor in determining safe speed under COLREGs?

• A. The hull's color.
• B. Visibility.
• C. Traffic density.
• D. Wind.

Answer: (A)

The main idea is that safe speed under COLREGs is about choosing a speed you can maintain so you can take proper and effective action to avoid collision given the current conditions. Factors that influence this decision include visibility, how crowded the area is (traffic density), wind and current (which affect maneuverability and stopping distance), sea state, the vessel’s own stopping and turning capabilities, and any navigational hazards.

The hull’s color does not affect any of these practical considerations. It doesn’t change how quickly you can stop, how well you can maneuver, or how easily other vessels will detect you, so it isn’t used in determining safe speed. The other factors—visibility, traffic density, and wind (and related conditions)—directly influence how much time and space you have to react and avoid a collision.