On 4 October your 1907 zone time DR position is LAT 25°15.0'S, LONG 105°44.0'E. At that time, you observe Deneb bearing 011.5°psc. The chronometer reads 00h 07m 42s, and the chronometer error is 00m 36s fast. The variation is 7.5°W. What is the deviation of the standard compass?

Question

On 4 October your 1907 zone time DR position is LAT 25&deg;15.0'S, LONG 105&deg;44.0'E. At that time, you observe Deneb bearing 011.5&deg;psc. The chronometer reads 00h 07m 42s, and the chronometer error is 00m 36s fast. The variation is 7.5&deg;W. What is the deviation of the standard compass?

Accepted Answer

Option A: 3.2&deg;E. Compute Greenwich Mean Time from zone time and chronometer data, extract GHA and declination from the Nautical Almanac, then solve the PZX triangle using Bowditch formulas to determine true bearing. Compare true bearing with standard compass bearing, applying variation to isolate the compass deviation.

On 4 October your 1907 zone time DR position is LAT 25&deg;15.0'S, LONG 105&deg;44.0'E. At that time, you observe Deneb bearing 011.5&deg;psc. The chronometer reads 00h 07m 42s, and the chronometer error is 00m 36s fast. The variation is 7.5&deg;W. What is the deviation of the standard compass?

On 4 October your 1907 zone time DR position is LAT 25°15.0'S, LONG 105°44.0'E. At that time, you observe Deneb bearing 011.5°psc. The chronometer reads 00h 07m 42s, and the chronometer error is 00m 36s fast. The variation is 7.5°W. What is the deviation of the standard compass?