On 26 May your 0723 zone time DR position is LAT 24°50.0'N, LONG 38°11.0'W. At that time, you observe the Sun bearing 076.5°psc. The chronometer reads 10h 25m 43s, and the chronometer error is 02m 57s fast. The variation is 7°W. What is the deviation of the standard magnetic compass?

Question

On 26 May your 0723 zone time DR position is LAT 24&deg;50.0'N, LONG 38&deg;11.0'W. At that time, you observe the Sun bearing 076.5&deg;psc. The chronometer reads 10h 25m 43s, and the chronometer error is 02m 57s fast. The variation is 7&deg;W. What is the deviation of the standard magnetic compass?

Accepted Answer

Option D: 10.7&deg;E. Calculate the Sun's declination for 26 May. Determine the true amplitude using sin(Amp) = sin(Dec) / cos(Lat). Convert the true amplitude to a true bearing. Apply the 7°W variation to the compass bearing of 076.5°psc to find the magnetic bearing. The difference between true and magnetic bearings results in 10.7°E deviation.