This doesn't answer your question, but... If you're going to use the GPS for positioning, make sure you get one with a 10' scale. I have an Etrex (cheap, yellow model from Walmart) and a Garmin (cheap orange one from Walmart), both have a 20' range that makes finding brush piles tough. I use the Gps on my Humminbird depth finder for locating cover. It has a 10' scale and makes finding stuff a LOT easier and faster.