Risk of collision exists when an approaching vessel has a generally steady range and increasing bearing.

Risk of collision exists when an approaching vessel has a generally steady range and increasing bearing.

• A. Generally steady range and increasing bearing
• B. Rapidly changing range
• C. Decreasing bearing with changing range
• D. No chance of collision

Answer: (A)

A vessel is at risk of collision when the other ship’s relative motion indicates a potential crossing path, even if you aren’t yet getting any closer. If the distance between you stays roughly the same (generally steady range) but the other vessel’s bearing is increasing, the line of sight to that vessel is rotating across your bow. That means the other vessel is moving sideways relative to you in such a way that, if you both maintain your present courses and speeds, your paths could intersect. This is a classic warning cue to take early action to avoid a close-quarters situation. Rapidly changing range would imply the distance is actively opening or closing, which is a different signal. Decreasing bearing with changing range suggests the other vessel’s bearing is moving toward your bow, but it describes a different relative motion. No chance of collision would ignore the rotating bearing cue that signals a potential crossing.

A vessel is at risk of collision when the other ship’s relative motion indicates a potential crossing path, even if you aren’t yet getting any closer. If the distance between you stays roughly the same (generally steady range) but the other vessel’s bearing is increasing, the line of sight to that vessel is rotating across your bow. That means the other vessel is moving sideways relative to you in such a way that, if you both maintain your present courses and speeds, your paths could intersect. This is a classic warning cue to take early action to avoid a close-quarters situation.

Rapidly changing range would imply the distance is actively opening or closing, which is a different signal. Decreasing bearing with changing range suggests the other vessel’s bearing is moving toward your bow, but it describes a different relative motion. No chance of collision would ignore the rotating bearing cue that signals a potential crossing.