USCG Exam PracticeDanger bearings and danger circles
A vessel is approaching a rocky headland from seaward. Only one charted lighthouse is visible. The navigator wants to use a danger bearing to stay clear of the rocks. After constructing the danger bearing and labelling it NLT 032°T, the navigator should take which action on each subsequent observation?
- A. Advance the danger bearing along the DR track to the time of each new observation before comparing it to the observed bearing
- ✓ Compare each observed compass bearing to the lighthouse against the NLT 032°T limit and alter course if the bearing falls below 032°TCorrect
- C. Use the danger bearing as the first LOP in a running fix by advancing it to the time of the second bearing
- D. Discard the danger bearing once a two-object fix is obtained and rely solely on the fix for hazard avoidance
Why B is correct
Bowditch Ch. 7 §706 states that so long as the object's observed bearing stays on the safe side of the danger bearing, the vessel remains in safe water. For an NLT label the observed bearing must remain at or above 032°T; if it falls below, the vessel is standing toward the hazard and course must be altered. Advancing a danger bearing along the DR track is the procedure for a running fix, not a danger bearing.
Cited:Bowditch Ch. 7 §706