Chart Navigation & Plotting · Fixes — Distance by Two Bearings and Run
The most general method of finding distance off using two bearings of one object (not limited to special angles) requires knowing:
- AThe object's nominal range
- BOnly the charted height of the object
- COnly the time between bearings
- DThe two relative bearings and the distance run between them, then solving the oblique triangle✓ Correct
Explanation
The general two-bearings-and-run method uses both relative bearings and the run between them to solve the oblique triangle for distance off (via Bowditch Table 7 or the law of sines). Bow-and-beam and doubling-the-angle are convenient special cases.
Authority: Bowditch (Pub. No. 9), distance by two bearings
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