I use a Garmin e-trex to locate positions in the field where we don't want the trouble of using larger equipment on a Quad bike.
I took it up in the Cub last week fitted to a home made bulldog clip type bracket and it was great,OK it only gives direction and distance to waypoint, and speed over ground,when I headed back into a lightish wind my ground speed dropped to 45 mph!
I think it also gives elevation but have not used that to date,but what else do you need for local nav if conditions turn a bit murky and you need a bit of re-assurance?
It cost £99 new.
Lister