"Hi, just wondered if you had any easy ways of remembering how to calculate Magnetic Variation"?
The books are full of different expressions some easier to remember than others. We use a simple method, think of the chart as being a grid (The lines of Latitude and Longitude) remember this. "Grid to Mag (The Compass) Add the Westerly Variation, Mag to Grid (The chart) Get Rid of the Westerly Variation. Simply do the opposite for the Easterly. The formula works for Deviation in the same way - towards the Compass always add the Westerly. Email RYA Day Skipper Theory - A Question of Variation
