🔍 Key Concepts

• Great circle vs. rhumb line – how each behaves on a globe and on a Mercator chart • Effect of latitude and distance (longitude change) on the difference between great circle and rhumb line distance • How to use a gnomonic tracking chart to compare paths between two points

💭 Think About

• Which of these voyages covers the largest change in longitude at relatively high latitudes, where great circle savings are most noticeable? • If you plot the endpoints on a gnomonic chart, which pair produces the most curved great circle when transferred to a Mercator chart? • Which route is short and mostly north–south or coastal, meaning the rhumb line and great circle would be very similar?

✅ Before You Answer

• Identify which choices involve higher latitudes and longer east–west spans across the North Atlantic • Mentally estimate which voyages are relatively short coastal hops versus ocean passages • Remember: on a gnomonic chart, great circles plot as straight lines; consider where that straight line would bow farthest toward the pole when seen on a Mercator chart