In reply to UKC/UKH Articles:
Well, technically there's more than one correct answer there. What a thing is designed for and what it allows you to do are two different things.
Also..
"Clear Navigation"
Mm.. in the USA probably. Not so much if you're using a 1:25k map (eg: OS Explorer), because it has a 1:24k romer where a European compass would have 1:25k.