On 11 May your vessel's 1839 ZT position is LAT 17°30'N, LONG 63°55'W, when an amplitude of the Sun's center is observed on the celestial horizon bearing 301° per standard magnetic compass. Variation for this area is 10.5°W. The chronometer reads 10h 37m 10s and is 02m 08s slow. What is the deviation of the compass?

Correct Answer: Option B — 1.5°W

Find the Sun's declination for the date. Calculate the True Amplitude using sin(Amp) = sin(Dec) / cos(Lat). The difference between the True Amplitude and the compass bearing is the Compass Error. Applying the 10.5°W variation to the Compass Error yields a deviation of 1.5°W, following Bowditch celestial navigation methods.