On 16 December your 1810 zone time DR position is LONG 129°46.5' W. At that time you observe Polaris with a sextant altitude (hs) of 23°56.8'. The chronometer time of the sight is 03h 12m 31s, and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 52.6 feet. What is your latitude by Polaris?

Question

On 16 December your 1810 zone time DR position is LONG 129&deg;46.5' W. At that time you observe Polaris with a sextant altitude (hs) of 23&deg;56.8'. The chronometer time of the sight is 03h 12m 31s, and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 52.6 feet. What is your latitude by Polaris?

Accepted Answer

Option A: 23&deg;07.8'N. Polaris latitude calculation requires correcting the sextant altitude for index error, dip, and refraction to find Ho. Apply the Nautical Almanac's 'a0, a1, a2' corrections based on LHA Aries. The resulting latitude is 23°07.8'N, following the standard procedure for Polaris observations as outlined in Bowditch.