True north differs from magnetic north, which varies from place to place and over time due to local magnetic anomalies. A magnetic compass almost never shows true north. In fact over millions of years, magnetic north wanders considerable and occasionally reverses so that the magnetic north pole has been near the geographic south pole at some periods in the earth’s history. In the arctic region, a magnetic compass is not very useful. To find true north from a magnetic compass you have to know the local magnetic variation and how it is varying over time. For ordinary folk this is difficult (although good maps will have magnetic deviation marked on … Continue reading RedGrittyBrick