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

Accepted Answer

Option B: 51°35.4'W. Advance the 0938 ZT sun line to 1200 ZT using the vessel's course and speed. Calculate the longitude at LAN using the meridian altitude and the Equation of Time. Intersect the advanced line of position with the meridian longitude to determine the 1200 ZT running fix.