GPS vs Map & Compass
A GPS is a nice piece of gear but you should also be proficient with a 1:24,000 topographic map and compass. I carry a military lensatic compass with Tritium illumination and a topographic map for where I am going to be. Having the map laid out ahead of time allows for a map recon of the area in which you will be operating. There are great military manuals available that cover map and compass work. The best part of a map and compass is there are no batteries to replace or signal disruptions. I also get my maps laminated which makes them water proof and a good overhead shield from the unexpected rain storm. Contact me and I'll give you more info on where I get my gear.