On 21 November at 0430 ZT, morning stars...

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Question 1 of 2066636eea28f7522a1c51ac8e

On 21 November at 0430 ZT, morning stars were observed, and the vessel's position was LAT 22° 14.0' S, LONG 79° 23.0' E. Your vessel is steaming at 14.5 knots on a course of 246° T. A sextant observation of the Sun's lower limb is made at 0816 ZT. The chronometer reads 03h 14m 16s, and the sextant altitude (hs) is 44° 29.2'. The index error is 1.0' on the arc, and the chronometer error is 01m 47s slow. Your height of eye is 61.0 feet (18.6 meters). What is the azimuth (Zn) and intercept (a) of this sight using the assumed position method?

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Question 1 of 20

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🔍 Key Concepts

• Assumed position method for Sun sights (how you choose Lat and Long from DR for the sight reduction tables) • Correcting sextant altitude: index correction, dip (height of eye), and altitude corrections to get Ho • Comparing Ho (observed altitude) and Hc (computed altitude) to decide toward (T) vs away (A) and the azimuth Zn direction

💭 Think About

• Start by carefully converting the sextant altitude (hs) into Ho step by step. What sign is the index error, and what does "on the arc" mean for the correction? • Compute the DR position at the time of the Sun sight, then choose the assumed latitude and longitude you would use for sight reduction tables, and work through to find Hc and Zn. • When you compare Ho and Hc, think: if the observed altitude is greater than the computed altitude, is the intercept toward or away the GP of the Sun? How does that translate into the "T" or "A" in the answer choices?

✅ Before You Answer

• Be sure the chronometer error (slow/fast) is applied with the correct sign to get the right UTC/GMT for the sight. • Double-check the course and speed run from the earlier star fix time (0430 ZT) to the Sun sight time (0816 ZT) to get the correct DR position at the time of the Sun observation. • Verify the Zn quadrant: with the Sun’s position and your latitude in the Southern Hemisphere, should the azimuth be closer to 084° or 095°? Confirm whether it should be in the NE, SE, etc., based on local time and date.

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