On 26 January your 1615 ZT DR position is LAT 27°14.0'S, LONG 57°22.0'W. At that time, you observe the Sun bearing 266°psc. The chronometer reads 08h 13m 19s, and the chronometer error is 01m 46s slow. The variation is 4°E. What is the deviation of the standard magnetic compass?

Question

On 26 January your 1615 ZT DR position is LAT 27&deg;14.0'S, LONG 57&deg;22.0'W. At that time, you observe the Sun bearing 266&deg;psc. The chronometer reads 08h 13m 19s, and the chronometer error is 01m 46s slow. The variation is 4&deg;E. What is the deviation of the standard magnetic compass?

Accepted Answer

Option C: 5.9&deg;W. Determine the Sun's declination and the local hour angle using the corrected chronometer time. Calculate the true amplitude using the sine formula. Comparing the true amplitude to the compass bearing of 266°psc, and applying the 4°E variation, the remaining difference identifies the compass deviation as 5.9°W.

On 26 January your 1615 ZT DR position is LAT 27&deg;14.0'S, LONG 57&deg;22.0'W. At that time, you observe the Sun bearing 266&deg;psc. The chronometer reads 08h 13m 19s, and the chronometer error is 01m 46s slow. The variation is 4&deg;E. What is the deviation of the standard magnetic compass?

On 26 January your 1615 ZT DR position is LAT 27°14.0'S, LONG 57°22.0'W. At that time, you observe the Sun bearing 266°psc. The chronometer reads 08h 13m 19s, and the chronometer error is 01m 46s slow. The variation is 4°E. What is the deviation of the standard magnetic compass?