On 15 November your 0913 zone time fix gives you a position of LAT 22°30.0'N, LONG 68°28.0'W. Your vessel is on course 164°T, and your speed is 13.5 knots. Local apparent noon (LAN) occurs at 1118 zone time at which time meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 49°46.0'. What is the calculated latitude at LAN?

Question

On 15 November your 0913 zone time fix gives you a position of LAT 22&deg;30.0'N, LONG 68&deg;28.0'W. Your vessel is on course 164&deg;T, and your speed is 13.5 knots. Local apparent noon (LAN) occurs at 1118 zone time at which time meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 49&deg;46.0'. What is the calculated latitude at LAN?

Accepted Answer

Option C: 21&deg;39.3'N. Meridian altitude formula at Local Apparent Noon determines latitude using: Latitude = Dec +/- Zenit Distance. Declination is extracted from the Nautical Almanac for the exact GMT of LAN, and combined with corrected observed altitude.