On 12 September your 0600 zone time (ZT) fix gives you a position of LAT 22°51.9'N, LONG 133°40.1'W. Your vessel is on course 062°T, and your speed is 12.3 knots. Local apparent noon (LAN) occurs at 1142 ZT, at which time a meridian altitude of the Sun's upper limb is observed. The observed altitude (Ho) for this sight is 70°33.2'. What is the calculated latitude at LAN?

Question

Accepted Answer

Option A: 23°24.8'N. Advance the 0600 fix to the time of LAN (1142) using the course and speed. Calculate the Sun's declination at 1142 GMT. Use the meridian altitude formula: Latitude = (90° - Ho) ± Declination. Since the Sun is north of the observer, add the declination to the zenith distance.