For those looking for a portable GPS unit for on-foot activities such as hiking. Here are a few features that you should be on the look out for when making a purchase decision.This one is obvious, but make sure there is a visual map screen where you can see where you are relative to your surroundings. Some GPS receivers only tell you your longitude and latitude position.Make sure that the unit was designed to be rugged enough to work and last in the environment you are planning to trek at. Things such as being water proof, shock proof, and weather proof are helpful if possible.If you plan on trekking or camping for extended periods of time, you want a GPS unit that has a long battery life relative to the time you spend outdoors.It’s important to have preloaded maps so you can find nearby roads easily and not get lost. Make sure the unit you buy supports as many routes as you think you’ll need.Waypoints are a very handy feature. Make sure that your unit supports many user-entered waypoints.Make sure the receiver is light to carry and small enough to fit into your traveling gear. Also make sure that the screen is clear and easy to read at a glance so you don’t have to spend too much time fumbling around for directions.