On 4 July at 0630 ZT, morning stars were observed, and the vessel's position was determined to be LAT 21°15.0'S, LONG 21°20.0'W. Your vessel is steaming at 13.0 knots on a course of 146°T. A sextant observation of the Sun's lower limb is made at 0915 ZT. The chronometer reads 10h 14m 27s, and the sextant altitude is 25°29.8'. The index error is 3.1' off the arc, and the chronometer error is 0m 53s slow. Your height of eye on the bridge is 48.0 feet. What is the azimuth (Zn) of this sight using the assumed position?

Question

On 4 July at 0630 ZT, morning stars were observed, and the vessel's position was determined to be LAT 21&deg;15.0'S, LONG 21&deg;20.0'W. Your vessel is steaming at 13.0 knots on a course of 146&deg;T. A sextant observation of the Sun's lower limb is made at 0915 ZT. The chronometer reads 10h 14m 27s, and the sextant altitude is 25&deg;29.8'. The index error is 3.1' off the arc, and the chronometer error is 0m 53s slow. Your height of eye on the bridge is 48.0 feet. What is the azimuth (Zn) of this sight using the assumed position?

Accepted Answer

Option A: 049.5&deg;T. Per Bowditch instructions, advance the vessel's DR position for the time elapsed between sights, determine GMT, apply index error and dip corrections to the observed solar altitude, and solve the navigational triangle for the true azimuth.