On 22 February your 0612 zone time fix gives you a position of LAT 27°16.2'S, LONG 37°41.6'W. Your vessel is on course 298°T, and your speed is 14.2 knots. Local apparent noon (LAN) occurs at 1147 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 73°33.3'. What is the calculated latitude at LAN?

Question

On 22 February your 0612 zone time fix gives you a position of LAT 27&deg;16.2'S, LONG 37&deg;41.6'W. Your vessel is on course 298&deg;T, and your speed is 14.2 knots. Local apparent noon (LAN) occurs at 1147 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 73&deg;33.3'. What is the calculated latitude at LAN?

Accepted Answer

Option A: 26&deg;31.4'S. Calculate the latitude at LAN using the meridian altitude formula: Lat = (90° - Ho) ± Dec. Determine the Sun's declination for the time of LAN using the Nautical Almanac. Applying the observed Ho of 73°33.3' and the declination yields the calculated latitude of 26°31.4'S.