Just as an aside, I bought my first handheld GPS after inadvertently walking the wrong way down a mountain in Scotland. I was walking in cloud and didn't know (I do now !) that the mountain in question contained a lot of iron bearing rock, so my compass showed North (which happened to be correct) as I walked up it and South, whichever route I took down.
Mrs Genghis, who was with me at the time, was distinctly unimpressed and suggested quite strongly I should do something about my navigation, so I bought a GPS !
G