Non-mapping GPS usually weigh less than mapping units. . This is an important consideration if you want to carry the device in your pocket, less so if you're using it for your car or boat. Most handhelds weigh about 7 ounces. If you want to use your GPS outdoors, get a waterproof model . An IPX7 rating means that a model is waterproof to 1 meter for up to 30 minutes.
Battery life is generally shorter than manufacturers' claims .
If you think your interests or needs might change, look for an expandable model . Cheaper models, like the Garmin 12, have no options for map downloads from software, while the eMap is an expandable system. In addition to Metro Guide software, at least four other titles are available. The government lifted SA on May 2, 2000. The Global Positioning System is a network of 24 satellites in six different orbital paths.