On 7 November your 0830 zone time fix gives you a position of LAT 27°36.0'N, LONG 163°19.0'W. Your vessel is on course 289°T, and your speed is 19.0 knots. Local apparent noon (LAN) occurs at 1138 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 45°35.0'. What is the calculated latitude at LAN?

Question

On 7 November your 0830 zone time fix gives you a position of LAT 27&deg;36.0'N, LONG 163&deg;19.0'W. Your vessel is on course 289&deg;T, and your speed is 19.0 knots. Local apparent noon (LAN) occurs at 1138 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 45&deg;35.0'. What is the calculated latitude at LAN?

Accepted Answer

Option D: 27&deg;57.2'N. Meridian altitude latitude is calculated by finding the Sun's declination at LAN and applying the zenith distance. Using the formula Latitude = Declination + Zenith Distance (or vice versa depending on hemisphere), the calculated value is 27°57.2'N. This follows standard celestial navigation principles for determining latitude at local noon.