USCG Exam PracticeRunning fix from a single object
Why is a running fix considered less accurate than a fix obtained from two simultaneous LOPs?
- A. It relies on three LOPs that rarely intersect at a single point, forming a cocked hat
- ✓ It assumes course and speed were held exactly between the two observationsCorrect
- C. It corrects the DR position for estimated set and drift, introducing vector error
- D. It uses relative bearings rather than compass bearings, reducing precision
Why B is correct
Bowditch Ch. 7 §708 states the running fix is less reliable than a simultaneous two-object fix because it assumes course and speed were maintained exactly between observations. Any deviation in course or speed introduces error in the advanced LOP.
Cited:Bowditch Ch. 7 §708