On 17 May at 0501 zone time, morning stars were observed, and the vessel's position was determined to be LAT 22°16.0'S, LONG 103°46.0'W. Your vessel is steaming at 24.0 knots on a course of 301°T. A sextant observation of the Sun's lower limb is made at 0845 zone time. The chronometer reads 03h 43m 32s, and the sextant altitude is 28°24.7'. The index error is 1.5' off the arc, and the chronometer error is 02m 02s slow. Your height of eye on the bridge is 85.5 feet. What is the azimuth (Zn) of this sight using the assumed position?
• Running fix and DR position between 0501 and 0845 at 24.0 knots on course 301°T • Converting zone time to GMT using chronometer reading and chronometer error • Using the Sun’s computed altitude and azimuth (Zn) from the assumed position in the sight reduction process
• How do you advance the 0501 position to the 0845 time to get the correct assumed position for the sight? • Once you have GMT of the sight time, what tables or method do you use to obtain the Sun’s GHA and declination and then the azimuth? • When comparing the multiple‑choice answers, what does a small change in latitude or LHA do to the azimuth in this morning‑sun geometry (east or west shift)?
• Be sure you apply the chronometer error (slow/fast) with the correct sign to get the right GMT of the observation. • Confirm you used the correct Zn convention: measured clockwise from true north 000°–359°. • Double‑check that your assumed longitude puts local hour angle (LHA) in the correct 0°–360° range for a morning Sun and that your resulting Zn is generally in the correct quadrant (NE, SE, etc.).
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