SporTrak Map is a great GPS

I will have owned the Magellan SporTrak for over 3 years. I have been geocaching with this unit ever since I got it. I have found 32 geocaches with it, no problem. This unit is not a gps that surveyors use so you will not get sub meter accuracy. It does have WAAS capability built in though which stands for Wide Area Augmentation System. WAAS is a system set up by the department of defense to fix any error the satellite might generated. This gives the GPS unit an accuracy of 3 meters or below. No GPS unit has a greater accuracy without post processing software and those GPS units cost about $2000 or more. GPS technology has been around for thirty years or so but it was not widely used by the public until selective availability was turned off in the year 2000. I have the Mapsend software and some of the roads are off by maybe 20 meters or so. I also used the GPS unit in the airplane to track our flight and even going at 504 mph and 38000 ft above sea level it was still able to pick up satellites. (it was on southwest airlines). GPS units are safe to use on planes but make sure you check with your airline before using it. I have also used the GPS unit for work (I am a GIS Technician) and loaded the points into the computer and they came up on the aerials very accurately.