USCG Exam PracticePassing distance and CPA from chart plot
When observing a vessel on radar, you note that its compass bearing has remained constant over several observations while the range is steadily decreasing. What does this indicate?
- A. The vessel is on a reciprocal course and will pass port-to-port
- ✓ Risk of collision existsCorrect
- C. The vessel is crossing ahead and will pass safely
- D. The vessel is overtaking your vessel
Why B is correct
Bowditch Ch. 7 §704 states that if compass bearing remains constant and range is decreasing (CBDR), risk of collision exists. A constant bearing with decreasing range is the canonical indicator of collision risk regardless of the geometry of the encounter.
Cited:Bowditch Ch. 7 §704