What is the difference between 'safe speed' and 'minimum safe speed' under COLREGS?

• A. Safe speed is the slowest permissible speed to ensure safe maneuvering.
• B. Minimum safe speed is the fastest speed that still allows safe stopping.
• C. Safe speed is prudent for conditions; minimum safe speed is the slowest speed that still allows safe maneuvering and stopping to avoid collision.
• D. Safe speed and minimum safe speed mean the same thing.

Answer: (C)

Proceeding at a safe speed means choosing a pace that allows you to take proper and effective action to avoid collision given the current conditions. It’s a prudent speed tailored to factors like visibility, traffic, maneuverability, background lighting, weather, sea state, and the vessel’s equipment and handling.

Minimum safe speed refers to the slowest speed at which you can still safely maneuver to avoid collision and, if needed, stop within the available distance for the conditions. Going slower than this would compromise your ability to take evasive action or stop in time.

So, safe speed is the general prudent speed for the situation, while minimum safe speed is the lower bound—the slowest speed that still keeps you able to maneuver and stop to avert a collision.

The other ideas aren’t accurate because safe speed isn’t necessarily the slowest speed, and minimum safe speed isn’t the fastest; they aren’t the same, and they aren’t defined as the same concept.