On 16 February your 0640 zone time (ZT) position was LAT 23°46.0'N, LONG 156°24.0'W. Your vessel was steaming on course 222°T at a speed of 18.0 knots. An observation of the Sun's lower limb was made at 0910 ZT. The chronometer read 07h 08m 06s and was slow 01m 56s. The observed altitude (Ho) was 27°15.8'. LAN occurred at 1245 ZT (ZD +10). The observed altitude (Ho) was 55°25.3'. What was the longitude of your 1245 ZT running fix?

Question

Accepted Answer

Option C: 157°42.0'W. Calculate the LHA of the Sun at LAN using the Nautical Almanac. By applying the formula for longitude by meridian passage, the difference between GHA at LAN and the observed LHA determines the vessel's longitude. Following standard Bowditch procedures for a running fix, the resulting position is 157°42.0'W.