On 27 March your 0730 zone time position is LAT 28°16'N, LONG 56°37'W. Your vessel is on course 158°T at a speed of 15.0 knots. An observation of the Sun's lower limb is made at 0915 zone time. The chronometer reads 01h 14m 11s, and the chronometer error is 00m 53s slow. The observed altitude (Ho) is 45°10.7'. LAN occurs at 1150 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) is 65°32.8'. Determine the vessel's 1200 zone time position.

Question

On 27 March your 0730 zone time position is LAT 28&deg;16'N, LONG 56&deg;37'W. Your vessel is on course 158&deg;T at a speed of 15.0 knots. An observation of the Sun's lower limb is made at 0915 zone time. The chronometer reads 01h 14m 11s, and the chronometer error is 00m 53s slow. The observed altitude (Ho) is 45&deg;10.7'. LAN occurs at 1150 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) is 65&deg;32.8'. Determine the vessel's 1200 zone time position.

Accepted Answer

Option A: LAT 27&deg;08.8'N, LONG 56&deg;04.2'W. Determine the sun line of position using the intercept method and advance it to 1200 ZT. Combine this with the meridian altitude at LAN to establish the running fix. The intersection of the advanced LOP and the latitude at LAN provides the 1200 ZT position of 27°08.8'N, 56°04.2'W.