GPS + Maps = (maths x confusion)/"Argh!"

Took me donkeys yonks of getting a consistent 1.5km out before someone pointed out you have to change a setting on the damn thing make it use the right method of determining the curvature of the earth, "RTFM" I was told, "RTFM".

Tell you what they are good for though, apart from finding obscure rock art, is retracing your steps back to the path when the cloud comes down and you can't see nowt but moorland. But they're crap at doing the biz when surrounded by dense pinetrees.