What is the meaning of 'risk of collision' in navigation rules?

• A. The probability that vessels will come into contact if both continue at their present course and speed.
• B. The likelihood of weather changes affecting visibility.
• C. The chance of a signal being misread.
• D. The risk that a navigation buoy will drift.

Answer: (A)

In navigation rules, risk of collision means there is a possibility that two vessels will collide if they both continue on their present course and speed. It’s a statement about potential contact derived from relative motion—if two ships maintain their current tracks, their paths could intersect and the distance at the closest point of approach would be small enough to cause a collision. When such a risk exists, rules require taking early, clear action to avoid collision, typically by altering course, altering speed, or both, in a manner that is obvious to the other vessel.

This concept isn’t about weather affecting visibility, misreading signals, or a buoy drifting. Those issues affect safety in other ways, but they don’t define the likelihood of two vessels actually contacting each other under the ongoing tracks and speeds.