At 1542 ZT on 23 October, in DR position LAT 37° 28.5'N, LONG 156° 17.3'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 282.5°psc. The variation is 0.0°. What is the deviation?

Question

At 1542 ZT on 23 October, in DR position LAT 37&deg; 28.5'N, LONG 156&deg; 17.3'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 282.5&deg;psc. The variation is 0.0&deg;. What is the deviation?

Accepted Answer

Option A: 2.2&deg;E. Calculate the Moon's declination and GHA for the observation time. Determine the true amplitude using sin(Amp) = sin(Dec) / cos(Lat). Since variation is 0.0°, the true bearing equals the magnetic bearing. Comparing the calculated true bearing to the compass bearing of 282.5°psc results in a deviation of 2.2°E.

At 1542 ZT on 23 October, in DR position LAT 37&deg; 28.5'N, LONG 156&deg; 17.3'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 282.5&deg;psc. The variation is 0.0&deg;. What is the deviation?

At 1542 ZT on 23 October, in DR position LAT 37° 28.5'N, LONG 156° 17.3'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 282.5°psc. The variation is 0.0°. What is the deviation?