At 1538 ZT on 15 October, in DR position LAT 18° 12.8'S, LONG 160° 48.4'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 276.2°psc. Variation is 10°E. What is the deviation?

Question

At 1538 ZT on 15 October, in DR position LAT 18&deg; 12.8'S, LONG 160&deg; 48.4'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 276.2&deg;psc. Variation is 10&deg;E. What is the deviation?

Accepted Answer

Option D: 3.6&deg;W. Compute local hour angle and exact ephemeris data for the Moon. Apply standard Bowditch amplitude calculation methods to determine true bearing at the visible horizon, accounting for semi-diameter and parallax, then derive compass deviation using known variation.

At 1538 ZT on 15 October, in DR position LAT 18&deg; 12.8'S, LONG 160&deg; 48.4'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 276.2&deg;psc. Variation is 10&deg;E. What is the deviation?

At 1538 ZT on 15 October, in DR position LAT 18° 12.8'S, LONG 160° 48.4'E, you observe an amplitude of the Moon. The center of the Moon is on the visible horizon and bears 276.2°psc. Variation is 10°E. What is the deviation?