From Forces Network.
The phrase ‘Mag to grid, get rid & grid to mag, add’ is a simple mnemonic to help you remember how to make the correct adjustment after either taking a bearing using a magnetic compass or taking a grid bearing from a map.
So If you’re a fan of this forces’ favourite mnemonic to remind you how to make the correct calculations – by getting rid or adding the variation from magnetic north to grid north – it might no longer be as helpful as it used to be in some areas of the United Kingdom.
Particularly in the South West, the variation is now so small (0 Mils/degrees in Plymouth) that you’ll be able to effectively ignore the grid magnetic variation that changes each year.
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