A radar bearing of an approaching vessel that remains fairly constant as the range decreases indicates what?

A radar bearing of an approaching vessel that remains fairly constant as the range decreases indicates what?

• A. Safe passage
• B. No risk of collision
• C. Collision course requiring immediate action
• D. The target is stationary

Answer: (C)

Constant bearing with decreasing range signals a collision risk. When the radar shows the other vessel at essentially the same bearing as you close in, the line of sight between you stays fixed while distance shrinks, meaning you would reach the same point in space at the same time if you keep your current speed and course. That’s a collision course because you and the other vessel are on a converging path. Immediate action is required to avoid collision, such as altering course or adjusting speed to change the bearing and increase separation. The ideas of safe passage or no risk of collision would only apply if the bearing were changing and the vessels were not on a converging path; simply having a constant bearing as range decreases also indicates relative motion and not a stationary target.

Constant bearing with decreasing range signals a collision risk. When the radar shows the other vessel at essentially the same bearing as you close in, the line of sight between you stays fixed while distance shrinks, meaning you would reach the same point in space at the same time if you keep your current speed and course. That’s a collision course because you and the other vessel are on a converging path. Immediate action is required to avoid collision, such as altering course or adjusting speed to change the bearing and increase separation. The ideas of safe passage or no risk of collision would only apply if the bearing were changing and the vessels were not on a converging path; simply having a constant bearing as range decreases also indicates relative motion and not a stationary target.