On 12 June your 0400 ZT DR position is LAT 22°31.0'N, LONG 31°45.0'W. You are on course 240°T at a speed of 16.5 knots. What will be the zone time of sunrise at your vessel?
• Dead reckoning (DR) position and how to advance it to the time of the event (sunrise) using course and speed • Using the Nautical Almanac sunrise tables: selecting the correct date, latitude, and interpolation for longitude/time zone • Understanding zone time (ZT) vs GMT/UT and converting between them
• From 0400 ZT, how far (in time and distance) will your vessel travel along course 240°T before sunrise occurs at your shifted position? • How do you find the GMT/UT of sunrise for the relevant latitude and then adjust it for your longitude and time zone? • Does your DR position at sunrise fall closer to east or west longitudes within the same time zone, and how does that affect local sunrise time?
• Confirm the DR track and distance run from 0400 ZT to the approximate sunrise time using ( \text{Distance} = \text{Speed} \times \text{Time} ) • Verify you are using the correct time zone meridian for converting between longitude and zone time • Double-check that you have applied the longitude correction in the correct direction when converting from GMT/UT to zone time for sunrise
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