On 15 July in DR position LAT 22°19.0'N, LONG 154°37.0'W, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 298°psc. The chronometer reads 04h 45m 19s and is 01m 56s slow. Variation in the area is 7.5°W. What is the deviation of the standard magnetic compass?
Official USCG Answer & Rule Citation
Correct Answer: Option B — 3.0°E
Amplitude observations compute the true bearing of celestial bodies at the visible horizon. Subtracting variation from the calculated true bearing yields magnetic heading, and the difference against standard compass heading determines deviation.
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