To find a magnetic compass course from a...

Question 1 / 2707066636ee928f7522a1c51972f

Question 1 of 2707066636ee928f7522a1c51972f

To find a magnetic compass course from a true course what must you apply?

Question 1 of 27070

To find a magnetic compass course from a true course what must you apply?

🔍 Key Concepts

• True, Magnetic, Compass (T–M–C) relationships • Difference between variation and deviation • Standard memory aid: "True Virgins Make Dull Company" or similar T–M–C ladder

💭 Think About

• Start with TRUE course and think about what comes next before you get to the COMPASS course in the T–M–C sequence. • Ask yourself: which error comes from the Earth’s magnetic field, and which comes from the ship’s own magnetic influences? Do you have to correct for both to go all the way from TRUE to COMPASS? • Consider what would happen if you only applied one of these: would you end up with a magnetic course, or a compass course?

✅ Before You Answer

• Be clear on definitions: variation = chart value from True to Magnetic, deviation = vessel’s compass error from Magnetic to Compass. • Check whether the question is asking for a final magnetic course or a compass course — read the wording very carefully. • Verify in your T–M–C diagram whether you pass through both variation and deviation when converting from TRUE to COMPASS.

Question 1 of 27070

To find a magnetic compass course from a true course what must you apply?

Deviation and variation

Magnetic anomalies (local disturbances)

Variation

Deviation