On 17 March your 0520 DR position is LAT 27°23.0'N, LONG 39°42.0'W. You observe an unidentified star bearing 110°T at an observed altitude (Ho) of 50°47.2'. The chronometer reads 08h 22m 15s, and is 01m 45s fast. What star did you observe?

Correct Answer: Option C — Altair

Convert chronometer time to GMT and determine the GHA of Aries. Calculate the LHA of the star using the DR longitude. By comparing the resulting declination and SHA against the Nautical Almanac for 17 March, Altair is identified as the star matching the observed altitude and bearing.