🔍 Key Concepts

• To determine longitude with a celestial body, think about whether you need a time-based event (like LAN – local apparent noon) or a specific bearing relative to East/West. • Consider what kind of bearing gives you information mostly about time rather than position across your track. • Think about the relationship between your course (209°T) and the bearing of the observed body: do you want the body roughly ahead/astern, abeam, or on an East/West line to help with longitude?

💭 Think About

• Ask yourself: when navigators traditionally determine longitude at sea with the sun, what kind of observation or event do they use? How is that related to the direction of the sun? • If you are on course 209°T, which choice would place the celestial body on or near an East–West line, and why might that matter for longitude? • Which bearing would change mostly with time of day rather than with small changes in your position along your track?

✅ Before You Answer

• Identify which bearings are roughly East–West and which are roughly North–South. • Consider how a meridian passage (sun crossing your local meridian) is used to determine longitude—what is the sun’s bearing at that moment? • Before picking an answer, be sure you’re choosing a bearing that mainly helps with time (longitude) rather than with range across your course (latitude).