At 0500 zone time on 21 August, your DR...

Question 1 of 2707066636eea28f7522a1c51a82c

At 0500 zone time on 21 August, your DR position is LAT 47°00'N, LONG 125°15'W. You are steering 000°T at a speed of 9.8 knots. What is the zone time of sunrise?

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Question 1 of 27070

At 0500 zone time on 21 August, your DR position is LAT 47°00'N, LONG 125°15'W. You are steering 000°T at a speed of 9.8 knots. What is the zone time of sunrise?

🔍 Key Concepts

• Nautical Almanac sunrise tables for the Sun on 21 August at about LAT 47°N • Difference between GMT (UT), Local Mean Time (LMT), and Zone Time (ZT) • Converting longitude to time using the zone description (time zone) for 125°15'W

💭 Think About

• First, think about how you would find the approximate UT of sunrise at your DR latitude for that date using the almanac tables. • Then consider how to adjust that UT for your longitude to get Local Mean Time, and from there to your Zone Time using the correct zone description. • Ask yourself whether the vessel’s motion between 0500 and sunrise will significantly change the DR position (and sunrise time), or if you can reasonably use the 0500 DR latitude for the sunrise calculation.

✅ Before You Answer

• Verify the correct zone description (ZD) for LONG 125°15'W (how many hours from Greenwich, and E or W?). • Check that you are using the correct page/column in the Nautical Almanac: date, latitude band, and Sun’s rise data (not transit or set). • Confirm that your time conversions are done in the right order: UT ↔ LMT ↔ ZT, with the correct sign for each longitude and zone correction.