At 1300 ZT on 9 May your DR position is LAT...

Question 1 of 2707066636eea28f7522a1c51aaa9

At 1300 ZT on 9 May your DR position is LAT 24° 00' N, LONG 83° 26' W. Determine the computed altitude (Hc) of the Sun for the assumed position nearest to the above given latitude and longitude, given a chronometer time of 07h 00m 00s.

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Question 1 of 27070

🔍 Key Concepts

• Using the given DR latitude and longitude to choose the correct assumed position from the Nautical Almanac tables • Finding the Sun’s GHA and Dec at the given chronometer time and converting to LHA for the assumed longitude • Using the appropriate sight reduction tables (or formulas) for Hc of the Sun at the chosen AP

💭 Think About

• How do you convert the chronometer time 07h 00m 00s to the Greenwich Hour Angle (GHA) of the Sun at 1300 ZT ship’s time? What time-zone relationship must be considered? • Once you have GHA and your assumed longitude, how do you calculate Local Hour Angle (LHA) and decide the sign (east or west)? • For the selected assumed latitude and LHA, what entries do you look up in the sight reduction tables (or compute) to get the Sun’s computed altitude (Hc)?

✅ Before You Answer

• Confirm you are using the correct date (9 May) and correct hour (07h) in the Nautical Almanac for the Sun • Verify your time-zone difference between ZT (ship’s time) and UTC before taking GHA • Double-check that your chosen assumed longitude is the nearest whole degree to the DR longitude and that you used it consistently when finding LHA and then Hc