Chart Navigation & Plotting · Fixes — Running Fix
When constructing a running fix from two bearings of the same object taken at different times, what must you do to the earlier line of position?
- AAdvance it along the course and distance run between the two observations✓ Correct
- BRotate it by the gyro error
- CRetire it by the set and drift only
- DLeave it unchanged and cross it directly
Explanation
A running fix crosses LOPs taken at different times. The earlier LOP is advanced parallel to itself along the direction and distance the vessel ran (ideally the course/distance over ground), then crossed with the later LOP to obtain the running fix.
Authority: Bowditch (Pub. No. 9), running fix
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