From magnetic to true: which statement correctly describes the conversion steps?

• A. From magnetic to true: Add easterly variation to magnetic direction and subtract westerly variation from magnetic direction
• B. From magnetic to true: Subtract easterly variation from magnetic direction
• C. From magnetic to true: Add westerly variation to true direction and subtract easterly variation from true direction
• D. From magnetic to true: Add easterly variation to true direction and subtract westerly variation from true direction

Answer: (A)

Converting from magnetic to true bearings uses the variation between magnetic north and true north, with the convention that easterly variation is added and westerly variation is subtracted. The true bearing = magnetic bearing + variation, where variation is positive for east and negative for west. So you add easterly variation to the magnetic direction and subtract westerly variation from it to get the true direction. For example, a magnetic bearing of 030 degrees with east variation of 10 degrees yields a true bearing of 040 degrees; if the variation is west 10 degrees, the true bearing would be 020 degrees. The other options describe applying variation in the wrong way or starting from the wrong direction, which isn’t how the conversion from magnetic to true is performed.