On 10 November your 1630 zone time DR...

Question 1 of 2707066636eea28f7522a1c51a9d3

On 10 November your 1630 zone time DR position is LAT 25°10.0'N, LONG 71°12.0'W. You are on course 335°T at a speed of 24 knots. What will be the zone time of sunset at your vessel?

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Question 1 of 27070

On 10 November your 1630 zone time DR position is LAT 25°10.0'N, LONG 71°12.0'W. You are on course 335°T at a speed of 24 knots. What will be the zone time of sunset at your vessel?

🔍 Key Concepts

• Using the Nautical Almanac sunset tables for a given date and latitude • Converting between Greenwich mean time (GMT/UT), local mean time (LMT), and zone time (ZT) using the correct zone description (ZD) • Updating a dead-reckoning (DR) position for run between two times using course and speed

💭 Think About

• First, at 25°N on 10 November, what is the approximate GMT (or LMT) of sunset from the Almanac tables before any corrections for longitude or run? • Given longitude 71°12.0'W, what is the correct time correction (in hours and minutes) to go between GMT and LMT, and then between LMT and your zone time? • From 1630 ZT until sunset, how far could the vessel travel at 24 knots, and how much would that change the DR longitude and thus the time correction, if at all?

✅ Before You Answer

• Be sure you are using the correct time zone and sign of the zone description (ZD) for 71°W (compare with standard time meridians 60°W, 75°W, etc.) • Double-check your longitude-to-time conversion: 15° of longitude = 1 hour of time, so 1° = 4 minutes of time • Confirm whether the small change in DR position between 1630 and sunset would materially change your sunset time enough to move it to a different multiple of 5 minutes among the answer choices