On 30 August your 0554 zone time (ZT) position was LAT 25°39.0'S, LONG 31°51.0'E. Your vessel was steaming on course 325°T at a speed of 15.0 knots. An observation of the Sun's lower limb was made at 0836 ZT. The chronometer read 06h 38m 36s and was fast 02m 24s. The observed altitude (Ho) was 30°49.2'. LAN occurred at 1157 ZT. The observed altitude (Ho) was 56°40.0'. What was the longitude of your 1157 ZT running fix?

Question

On 30 August your 0554 zone time (ZT) position was LAT 25&deg;39.0'S, LONG 31&deg;51.0'E. Your vessel was steaming on course 325&deg;T at a speed of 15.0 knots. An observation of the Sun's lower limb was made at 0836 ZT. The chronometer read 06h 38m 36s and was fast 02m 24s. The observed altitude (Ho) was 30&deg;49.2'. LAN occurred at 1157 ZT. The observed altitude (Ho) was 56&deg;40.0'. What was the longitude of your 1157 ZT running fix?

Accepted Answer

Option D: 30&deg;52.5'E. Determine the longitude at LAN by comparing the observed meridian altitude to the calculated zenith distance. Using the Sun's declination from the Nautical Almanac, solve for latitude. Advance the 0836 ZT sun line to the time of LAN (1157 ZT) using the run between sights to intersect the meridian line.