When shall risk of collision be deemed to exist?

• A. When The Vessels Are On Reciprocal Courses
• B. If The Bearing Of An Approaching Vessel Does Not Appreciably Change
• C. When One Vessel Is Overtaking
• D. When Vessels Are Within One Mile

Answer: (B)

Risk of collision exists when the bearing of the approaching vessel does not appreciably change. If, as time passes, the other vessel’s apparent direction in your sight line stays nearly fixed, you and the other vessel are on a collision course if you both continue on your current speeds and headings. That situation calls for early, substantial action to avoid collision.

Being on reciprocal courses by itself isn’t enough to declare risk, because you might still pass safely if the bearing begins to change and the vessels diverge. Overtaking is a different scenario governed by its own rules, where the risk assessment and required actions follow that specific situation. And a fixed distance like one mile isn’t a reliable threshold for risk—the important factor is the relative geometry indicated by the bearing behavior, not a set range.