Magnetic declination can vary by more than 5 degrees. Imagine standing between true north and magnetic north, then the compass will be 180 degrees off. Also,

Magnetic declination can vary by more than 5 degrees. Imagine standing between true north and magnetic north, then the compass will be 180 degrees off. Also, the location of the magnetic north pole changes over time, and moves about 35 miles per year. (Wikipedia has a cool animation of the changes over time since the year 1590). http://en.wikipedia.org/wiki/Magnetic_declination http://en.wikipedia.org/wiki/Magnetic_declination http://en.wikipedia.org/wiki/North_Magnetic_Pole http://en.wikipedia.org/wiki/North_Magnetic_Pole