🔍 Key Concepts

• Converting between true, magnetic, and compass (psc) courses using variation and deviation • How to use the deviation table correctly based on the magnetic heading, not the compass heading • Plotting the course from the anchorage position to a point 0.5 NM east of Cape Charles Lighted Bell Buoy 14 on Chart 12221TR

💭 Think About

• First, on the chart, carefully plot the position of the anchorage and the point 0.5 NM east of Buoy 14, then measure the true course from the anchorage to that point. What approximate true course do you get? • Once you have the true course, think through the order of applying variation and deviation to end up with a course per standard compass (psc). Are you going from true to compass, or compass to true? • Look at the deviation table: you must enter it with the magnetic heading. After applying variation to your true course, what is the closest magnetic heading, and what deviation value does that give you?

✅ Before You Answer

• Be sure you’re applying variation 10° W with the correct sign when going from true to magnetic (remember the standard memory aids, like "East is least, West is best" or "Can Dead Men Vote Twice At Elections"). • Confirm you used the magnetic course (after applying variation) when entering the deviation table, not the compass course. • After converting to a compass course, compare your result to the answer choices and check which one is closest to your calculated psc, considering possible small plotting/measuring errors.