On May 20 your 2300, (ZD +4), DR position is LAT 42°07'N, LONG 81°02'W. At that time, you observe Polaris bearing 012°psc. The chronometer time of the observation is 03h 02m 23s, and the chronometer is 1m 17s fast. The variation is 9.5°W. What is the deviation of the magnetic compass?

Question

On May 20 your 2300, (ZD +4), DR position is LAT 42&deg;07'N, LONG 81&deg;02'W. At that time, you observe Polaris bearing 012&deg;psc. The chronometer time of the observation is 03h 02m 23s, and the chronometer is 1m 17s fast. The variation is 9.5&deg;W. What is the deviation of the magnetic compass?

Accepted Answer

Option A: 2.7&deg;W. Determine the true azimuth of Polaris using the Nautical Almanac. Compare the true azimuth to the compass bearing (012°psc) corrected for variation (9.5°W) and deviation. Solving the equation True = Compass + Variation + Deviation yields a deviation of 2.7°W.