Old-School Nav­i­ga­tion

What to Do When Your GPS Goes Down

RECOIL OFFGRID - - Contents - By Ryan Cleck­ner

What to Do When Your GPS Goes Down

How hard can it be? Af­ter all, if you want to go “up” on a map, you just fol­low the di­rec­tion that your com­pass is point­ing, right? Well, it’s ac­tu­ally a bit more com­pli­cated than that.

There are three dif­fer­ent “norths” — true north, mag­netic north, and grid north.

True north refers to the very top of the globe (the North Pole), mag­netic north is where the north-seek­ing ar­row of your com­pass points, and grid north is the di­rec­tion the ver­ti­cal grid lines on your map point. Why are they dif­fer­ent, and how does this af­fect your abil­ity to nav­i­gate ac­cu­rately? Fol­low along to find out.

True North and Mag­netic North

True north and mag­netic north are dif­fer­ent be­cause, de­spite what many be­lieve, the North Pole isn’t mag­netic and your com­pass doesn't point there. In­stead, your com­pass points to a gi­ant ore de­posit in North­ern Canada. There­fore, de­pend­ing on where you’re stand­ing in the world, your com­pass may ac­tu­ally point off to the side of true north.

For ex­am­ple, in parts of Ten­nessee and Alabama, mag­netic north and true north are in line with each other so there’s no per­cep­ti­ble dif­fer­ence be­tween the two at that lo­ca­tion.

How­ever, the vari­ance gets worse the fur­ther east or west you are. For ex­am­ple, in parts of Ge­or­gia, your com­pass will in­di­cate a few de­grees west of the North Pole. In Maine, your com­pass will be a stag­ger­ing 16 de­grees west of true north.

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