I was using my Garmin etrex Legend H for some elevation work in the bush. I wanted to know how much fall there was between the start and end of my mainline. So I punched in the end of the mainline. I then went up the hill directly to the north of the mainline end and it was a lower elevation then at the bottom of the crick. Went back the next week stood in the same spot at the end of the mainline and it was a totally different number.

Do I need a better GPS? Would we be using the same satellites in Canada as the US?