On 12 September your 0736 zone time DR position is LAT 28°34.0'S, LONG 174°49.0'E. At that time, you observe the Sun bearing 084° per standard magnetic compass (psc). The chronometer reads 07h 38m 11s, and the chronometer error is 01m 46s fast. The variation is 11°W. What is the deviation of the standard magnetic compass?

Question

On 12 September your 0736 zone time DR position is LAT 28&deg;34.0'S, LONG 174&deg;49.0'E. At that time, you observe the Sun bearing 084&deg; per standard magnetic compass (psc). The chronometer reads 07h 38m 11s, and the chronometer error is 01m 46s fast. The variation is 11&deg;W. What is the deviation of the standard magnetic compass?

Accepted Answer

Option B: 3.2&deg;E. Calculate the Sun's declination and the true amplitude using the observer's latitude. The true amplitude is compared to the compass bearing of 084°psc. Adjusting for the 11°W variation, the difference between the true and magnetic bearings results in a compass deviation of 3.2°E.