On 28 September in DR position LAT 24°12.0'S, LONG 85°25.0'E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 094°psc. The chronometer reads 11h 29m 42s and is 03m 30s slow. Variation in the area is 4°W. What is the deviation of the magnetic compass?

Question

On 28 September in DR position LAT 24&deg;12.0'S, LONG 85&deg;25.0'E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 094&deg;psc. The chronometer reads 11h 29m 42s and is 03m 30s slow. Variation in the area is 4&deg;W. What is the deviation of the magnetic compass?

Accepted Answer

Option D: 2.4&deg;E. Determine the Sun's declination for the observation time. Calculate the true amplitude using sin(Amp) = sin(Dec) / cos(Lat). Convert the true amplitude to a true bearing (090° ± Amp). Comparing this true bearing to the magnetic bearing (psc bearing corrected for 4°W variation) yields a deviation of 2.4°E.