The magnetic deviation of a compass needle depends upon your location. You need a rough idea of where you are in order to apply it. It is east of north in the western part in the USA and west of north east of the Mississippi River. A magnetic deviation map of the world is shown at
http://upload.wikimedia.org/wikipedia/commons/2/28/Mv-world.jpg
Hi! I am in a NROTC Navigation class and I am having trouble finding the deviation when converting compass readings to true degrees...idk if anyone can help me...thought I would ask..Thanks
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one of the nice ways to get it exact for your location is to use GPS to determine true north, then look at your magnetic compass. The difference is deviation.
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