On 11 May in DR position LAT 37°06.0'N, LONG 45°45.0'W you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 089.0°psc. The chronometer reads 07h 57m 06s and is 01m 48s slow. Variation in the area is 20.0°W. What is the deviation?

Question

On 11 May in DR position LAT 37&deg;06.0'N, LONG 45&deg;45.0'W you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 089.0&deg;psc. The chronometer reads 07h 57m 06s and is 01m 48s slow. Variation in the area is 20.0&deg;W. What is the deviation?

Accepted Answer

Option B: 2.2&deg;W. Determine the Sun's declination for 11 May. Calculate the true amplitude using sin(Amp) = sin(Dec) / cos(Lat). Convert the true amplitude to a true bearing. Adjust the compass bearing of 089.0°psc by the 20.0°W variation to find the magnetic bearing. The difference between true and magnetic bearings results in 2.2°W deviation.

On 11 May in DR position LAT 37&deg;06.0'N, LONG 45&deg;45.0'W you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 089.0&deg;psc. The chronometer reads 07h 57m 06s and is 01m 48s slow. Variation in the area is 20.0&deg;W. What is the deviation?

On 11 May in DR position LAT 37°06.0'N, LONG 45°45.0'W you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 089.0°psc. The chronometer reads 07h 57m 06s and is 01m 48s slow. Variation in the area is 20.0°W. What is the deviation?