When changing from a compass course to a...

When changing from a compass course to a...

Question 1 of 2707066636ee928f7522a1c5192b9

When changing from a compass course to a true course, which should you apply?

Question 1 of 27070

Q

When changing from a compass course to a true course, which should you apply?

🔍 Key Concepts

• Compass vs. true course and the standard conversion sequence (True–Variation–Magnetic–Deviation–Compass) • The difference between variation (chart/magnetic north difference) and deviation (compass error from ship’s magnetism) • Which corrections apply when you start from a compass course and want to end at a true course

💭 Think About

• Ask yourself: in the TVMDC sequence, where does compass course sit, and where does true course sit? • From compass to true, are you moving up or down the TVMDC ladder, and which steps do you pass through? • Which of the listed options are actually part of the magnetic/compass error corrections and which relate to something completely different (like current)?

✅ Before You Answer

• Confirm that current set and drift affect your track over the ground, not the basic conversion between compass and true headings. • Recall the full TVMDC chain and identify which two letters correspond to chart/earth-based and compass-based errors. • Make sure you know that variation comes from the earth’s magnetic field (shown on the chart), while deviation comes from the vessel’s own magnetism (shown on the deviation card).