On 25 June your 0900 zone time DR position...

Question 1 of 2707066636eea28f7522a1c51ad9e

On 25 June your 0900 zone time DR position is LAT 24° 10.0' S, LONG 148° 30.0' W. Your vessel is on a course of 230° T at a speed of 18.0 knots. What is the zone time of local apparent noon (LAN)?

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Question 1 of 27070

On 25 June your 0900 zone time DR position is LAT 24° 10.0' S, LONG 148° 30.0' W. Your vessel is on a course of 230° T at a speed of 18.0 knots. What is the zone time of local apparent noon (LAN)?

🔍 Key Concepts

• Local Apparent Noon (LAN) occurs when the Sun is on your local meridian (LHA Sun = 0°) • Relationship between longitude and time (15° of longitude = 1 hour of time) • How to convert Greenwich Hour Angle (GHA) of the Sun to Local Hour Angle (LHA) using your longitude

💭 Think About

• From your 0900 ZT DR position, think about how you would estimate the longitude of your vessel at the moment of LAN given your course and speed • Consider how many minutes of time correspond to the difference in longitude between your 0900 position and your estimated longitude at LAN • Think about how you would use the Nautical Almanac: find when the Sun’s GHA will equal (or differ from) your longitude by 360° to determine the time of meridian passage at your approximate longitude

✅ Before You Answer

• Be sure you are using zone time (ZT) consistently—watch the sign and offset from GMT/UT • Verify that you have correctly accounted for the vessel’s run between 0900 and LAN when updating your DR longitude • Check your final time against whether it makes sense physically: LAN near 1200 local apparent time, plus or minus the correction due to your longitude within the time zone