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?

Correct Answer: Option C — 2.7°W

Determine Greenwich Mean Time and Local Hour Angle of Aries to extract the Polaris correction from the Nautical Almanac, establishing the true bearing. Comparing true bearing with the standard compass bearing (psc) provides total compass error; removing variation (9.5°W) leaves a deviation of 2.7°W.