Magnetic or True North? in GPS Posted July 10, 2019 · Edited July 10, 2019 by Forkeye Wherever you live you will have a declination, that is the number of degrees difference between true north and magnetic north. It can be east or west. So with true north set you will face true north and with magnetic north set you will face magnetic north. As already mentioned it won’t make any difference for caching or most navigating. It will become important when you use a handheld compass and paper map with your gps or if you are given a bearing to follow to a waypoint or cache, you’ll always have to work in true or magnetic readings or else convert one to the other.