On 12 February your 0542 zone time (ZT) fix gives you a position of LAT 26°42.0'N, LONG 60°18.0'W. Your vessel is on course 300°T, and your speed is 9.8 knots. Local apparent noon (LAN) occurs at 1220 ZT at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 49°10.0'. What is the calculated latitude at LAN?

Question

On 12 February your 0542 zone time (ZT) fix gives you a position of LAT 26&deg;42.0'N, LONG 60&deg;18.0'W. Your vessel is on course 300&deg;T, and your speed is 9.8 knots. Local apparent noon (LAN) occurs at 1220 ZT at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 49&deg;10.0'. What is the calculated latitude at LAN?

Accepted Answer

Option B: 27&deg;16.3'N. At LAN, the latitude is calculated using the formula: Lat = (90° - Ho) ± Dec. Determine the Sun's declination for the time of LAN using the Nautical Almanac. Applying the observed Ho of 49°10.0' and the declination yields the calculated latitude of 27°16.3'N.