USCG Exam PracticeThree-bearing fix and cocked-hat triangle
A navigator observes that the compass bearing to an approaching vessel has remained constant over several minutes while the range has been decreasing. What conclusion must the navigator draw?
- A. The approaching vessel is on a reciprocal course and will pass clear
- ✓ Risk of collision existsCorrect
- C. The approaching vessel is crossing ahead and will pass clear
- D. A running fix should be computed before any action is taken
Why B is correct
Bowditch Ch. 7 §704 states that if the compass bearing to an approaching vessel remains constant and the range is decreasing (CBDR — constant bearing, decreasing range), risk of collision exists. This is the canonical method of detecting collision risk.
Cited:Bowditch Ch. 7 §704