🔍 Key Concepts

• Using the Nautical Almanac daily pages to find the GMT (UT) of sunset at a given latitude and date • Converting between GMT (UT), local mean time (LMT), and zone time (ZT) using longitude and zone description (ZD) • Projecting your vessel’s DR position ahead in time along course and speed to get the approximate latitude and longitude at sunset

💭 Think About

• First, should you use the 1300 ZT DR position as‑is, or do you need to estimate where the vessel will be at the time of sunset based on course and speed? • Once you have the UT of sunset from the Nautical Almanac for the correct latitude and date, how do you adjust it for your longitude to get local mean time, and then apply the correct zone description (ZD) to reach zone time? • Given your longitude near 079°E, what is the most likely time zone (ZD) in hours from GMT, and does that make sunset earlier or later in zone time compared with UT?

✅ Before You Answer

• Make sure you use the correct latitude band and date (10 December) in the Nautical Almanac sunset tables. • Confirm your zone description (ZD) from your longitude: 15° of longitude corresponds to 1 hour of time difference from GMT, east longitudes usually giving positive ZD. • After converting UT → LMT → ZT, check that the resulting sunset time is later than 1300 ZT and that your DR run from 1300 ZT to that time is consistent with your assumed position.