Which term is used to describe the angular difference between True North and Magnetic North?

• A. Variation
• B. Declination
• C. Latitude difference
• D. Azimuth difference

Answer: (A)

The angular difference between True North and Magnetic North is called variation. On nautical charts, variation is shown as an angle in degrees East or West, indicating how far magnetic north is offset from true north at a specific location. This offset lets navigators convert between true bearings and magnetic bearings by applying the appropriate sign: add the variation when it’s East, and subtract it when it’s West. Declination is a related term used in scientific contexts, and is often used interchangeably, but on charts the term you’ll see and use for navigation is variation.