On 8 February your 0800 zone time position is LAT 21°55'S, LONG 52°27'W. Your vessel is on course 056°T at a speed of 17.5 knots. An observation of the Sun's lower limb is made at 0938 zone time, and the observed altitude (Ho) is 46°06.5'. The chronometer reads 12h 37m 23s, and the chronometer error is 1m 24s slow. LAN occurs at 1243 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 83°56.1'. Determine the vessel's 1200 zone time position.

Question

On 8 February your 0800 zone time position is LAT 21&deg;55'S, LONG 52&deg;27'W. Your vessel is on course 056&deg;T at a speed of 17.5 knots. An observation of the Sun's lower limb is made at 0938 zone time, and the observed altitude (Ho) is 46&deg;06.5'. The chronometer reads 12h 37m 23s, and the chronometer error is 1m 24s slow. LAN occurs at 1243 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 83&deg;56.1'. Determine the vessel's 1200 zone time position.

Accepted Answer

Option D: LAT 21&deg;04.0'S, LONG 51&deg;21.5'W. Calculate the meridian passage using the Sun's declination and the vessel's latitude. By solving the meridian altitude formula (Ho = 90° - Lat ± Dec), determine the latitude at LAN. Advance the morning sun line to 1200 ZT using the vessel's speed and course to establish the final running fix position.