Originally Posted By: MarshAviator
....Some people draw red magnetic lines on maps (aviation charts have them printed in magenta)
The only problem with this is over time the secular variations (yearly changes) add up and you have to buy another map or carefully erase and redraw.

I don't prefer this, but like to make one line on the map which is magnetic so it is easily oriented with the compass....


I often set my uncorrected compass on the oriented map to draw the line.
It might not be surveyor accurate but it allows any compass to be used just by setting it on the line.

I find the confusion caused by magnetic, true and grid north can be a real problem for most people I meet.

(I must try to remember that about adding whiskey to virgins)

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May set off to explore without any sense of direction or how to return.