🔍 Key Concepts

• Mercator sailing between two positions on a chart • Using the change in latitude and longitude to find a track line • Plotting a course made good (CMG) rather than a planned course

💭 Think About

• First, sketch or plot both positions on a piece of graph paper or a plotting sheet. In which general direction did the vessel move (e.g., southeast, southwest)? • Look at the differences in latitude and longitude. Which change is greater—north/south or east/west—and what does that tell you about the approximate angle of the track? • After you get a rough visual direction, compare it with the answer choices and ask: which option best matches the direction and relative change in latitude vs. longitude?

✅ Before You Answer

• Confirm which way latitude changed (north or south) and which way longitude changed (east or west) to determine the general quadrant of the course (NE, SE, SW, NW). • Check that the approximate angle you visualize makes sense with the relative size of the lat vs. long changes—a larger change in latitude means a course closer to north–south; a larger change in longitude means closer to east–west. • Before picking, verify that your chosen course points from the first position exactly toward the second when sketched as a straight line.