On 21 February your 0823 zone time DR position is LAT 21°44.0'S, LONG 80°14.0'E. At that time, you observe the Sun bearing 096°psc. The chronometer reads 03h 25m 19s, and the chronometer error is 01m 52s fast. The variation is 5°W. What is the deviation of the standard magnetic compass?

Correct Answer: Option B — 4.7°W

Determine Greenwich Mean Time from chronometer time and error, find LHA using DR longitude, and execute sight reduction to extract computed azimuth (Zn). Compare Zn with the observed compass bearing to establish total compass error, and apply easterly or westerly variation to determine the deviation.