On 19 June your vessel's 0523 ZT DR position is LAT 25°12.0'N, LONG 123°14.0'W, when an amplitude of the Sun is observed. The Sun's center is on the visible horizon and bears 052.0° per standard compass. Variation in the area is 15°E. The chronometer reads 01h 21m 58s and is 01m 18s slow. What is the deviation of the standard compass?

Question

On 19 June your vessel's 0523 ZT DR position is LAT 25&deg;12.0'N, LONG 123&deg;14.0'W, when an amplitude of the Sun is observed. The Sun's center is on the visible horizon and bears 052.0&deg; per standard compass. Variation in the area is 15&deg;E. The chronometer reads 01h 21m 58s and is 01m 18s slow. What is the deviation of the standard compass?

Accepted Answer

Option D: 3.3&deg;W. Calculate the Sun's declination and LHA based on the corrected GMT. Determine the True amplitude using sin(Amp) = sin(Dec) / cos(Lat). The difference between the True bearing and the compass bearing (052.0°) provides the compass error. Applying the 15°E variation to this error identifies the deviation as 3.3°W.