On 5 September in DR position LAT 23°17.0'S, LONG 154°35.0'E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 275° per standard magnetic compass. The chronometer reads 07h 49m 26s and is 01m 52s fast. Variation in the area is 3°W. What is the deviation of the standard magnetic compass?

Question

On 5 September in DR position LAT 23&deg;17.0'S, LONG 154&deg;35.0'E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 275&deg; per standard magnetic compass. The chronometer reads 07h 49m 26s and is 01m 52s fast. Variation in the area is 3&deg;W. What is the deviation of the standard magnetic compass?

Accepted Answer

Option C: 5.1&deg;E. Calculate the Sun's declination and LHA using the Nautical Almanac. Determine the true amplitude (sin Amp = sin Dec / cos Lat). Compare the true amplitude to the compass amplitude (275°). Applying variation (3°W) to the true bearing yields a deviation of 5.1°E.