On 9 February your 0830 zone time DR position is LAT 22° 19.0' N, LONG 64° 37.0' E. Your vessel is on course 128° T at a speed of 19.0 knots. What is the zone time of local apparent noon?
• Local apparent noon (LAN) occurs when the Sun is on your local meridian • The time difference between your DR longitude and the standard meridian for your time zone affects LAN zone time • Your vessel’s motion along the track between 0830 and LAN changes your longitude and therefore the LAN time
• From 0830 DR position and course/speed, estimate where you will be (longitude) around the time of LAN • Determine your time zone based on DR longitude, then find the standard meridian for that zone • Use the difference in longitude between your estimated LAN longitude and the standard meridian to find how many minutes before or after 1200 LAN will occur
• Convert course and speed into an east–west (change of longitude) component between 0830 and your estimated LAN time • Be sure you are using the correct time zone for 64°–65°E (width is 15° of longitude per zone) • Convert the final time offset from degrees of longitude to minutes of time carefully, checking the sign (earlier vs later than 1200)
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