On 1 July your 0515 zone time fix gives you a position of LAT 23°24.0'S, LONG 151°42.0'W. Your vessel is on course 240°T, and your speed is 10.0 knots. Local apparent noon (LAN) occurs at 1215 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 42°55.0'. What is the latitude at 1200 ZT?

Question

On 1 July your 0515 zone time fix gives you a position of LAT 23&deg;24.0'S, LONG 151&deg;42.0'W. Your vessel is on course 240&deg;T, and your speed is 10.0 knots. Local apparent noon (LAN) occurs at 1215 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 42&deg;55.0'. What is the latitude at 1200 ZT?

Accepted Answer

Option C: 23&deg;59.7'S. Determine the latitude at LAN using the meridian altitude formula: Latitude = (90° - Ho) ± Declination. Advance the 0515 fix to 1200 using the course and speed. The resulting latitude at 1200 ZT is 23°59.7'S, calculated by applying the run to the meridian observation.