On 8 February your 0800 zone time (ZT) position was LAT 28°55.0'S, LONG 52°27.0'W. Your vessel was steaming on course 036°T at a speed of 19.0 knots. An observation of the Sun's lower limb was made at 0938 ZT. The chronometer read 12h 37m 23s and was slow 01m 24s. The observed altitude (Ho) was 45°29.2'. Local Apparent Noon (LAN) occurred at 1240 ZT. The observed altitude (Ho) was 77°10.5'. What was the longitude of your 1200 ZT running fix?

Question

On 8 February your 0800 zone time (ZT) position was LAT 28&deg;55.0'S, LONG 52&deg;27.0'W. Your vessel was steaming on course 036&deg;T at a speed of 19.0 knots. An observation of the Sun's lower limb was made at 0938 ZT. The chronometer read 12h 37m 23s and was slow 01m 24s. The observed altitude (Ho) was 45&deg;29.2'. Local Apparent Noon (LAN) occurred at 1240 ZT. The observed altitude (Ho) was 77&deg;10.5'. What was the longitude of your 1200 ZT running fix?

Accepted Answer

Option D: 51&deg;35.4'W. Solve 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 longitude of 51°35.4'W.