My suggestion is "be expert with map and compass". its loaded with exercises to practice.
http://www.beexpertwithmapandcompass.com/www.beexpertwithmapandcompass.com/Welcome.html

consider also teaching them to learn pace counting; keeping track of distance with ranger pace counter beads is an excellent skill that doesn't require batteries! There are tons of commercially available sets w/ craft store type beads, and some one-of a kind like mine.