USCG Exam PracticePlot true course and distance between two charted points
A navigator observes a relative bearing of 030° on a charted object, then continues on the same course until the relative bearing doubles to 060°. The distance run between the two bearings is 1.5 nautical miles. What is the vessel's distance from the object at the time of the second bearing?
- A. 0.75 nautical miles
- B. 1.0 nautical miles
- ✓ 1.5 nautical milesCorrect
- D. 3.0 nautical miles
Why C is correct
Bowditch Ch. 7 §703 states that when using the doubling-the-angle technique, the distance run between the two bearings equals the distance to the object at the time of the second bearing. Therefore 1.5 NM run equals 1.5 NM off at the second bearing.
Cited:Bowditch Ch. 7 §703