Navigation Problems USCG Question #245 (Set 7)

On 2 January your 1759 zone time DR longitude is 45°17.6' W. At that time you observe Polaris with a sextant altitude (hs) of 24°16.5'. The chronometer time of the sight is 08h 57m 10s, and the chronometer error is 02m 16s slow. The index error is 3.5' on the arc, and the height of eye is 42.5 feet. What is your latitude by Polaris?

Official USCG Answer & Rule Citation

Correct Answer: Option D — 23°18.8'N

Calculate the LHA of Aries using the chronometer time and longitude. Correct the sextant altitude for index error, dip, and refraction to find Ho. Apply the three Polaris correction tables (a0, a1, a2) to Ho to determine the latitude, which results in 23°18.8'N per standard celestial navigation protocols.

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