On 11 November your 0730 zone time position was LAT 19°58.0'N, LONG 143°54.0'W. Your vessel was steaming on course 084°T at a speed of 15.0 knots. An observation of the Sun's lower limb was made at 0931 ZT. The chronometer read 07h 29m 22s and was slow 02m 22s. The observed altitude (Ho) was 44°17.6'. LAN occurred at 1125 zone time (ZD +10). The observed altitude (Ho) was 52°17.4'. What was the longitude of your 1200 zone time running fix?
Official USCG Answer & Rule Citation
Correct Answer: Option A — 142°40.2'W
Utilizing the running fix method, the 0730 position is advanced to the time of the sun sight. By calculating the intercept and applying the change in longitude between the morning sight and LAN, the vessel's position at 1200 is determined to be 142°40.2'W.
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