The features needed for hiking different from those needed for other GPS applications, such as car navigation, running, boating, or golfing. Below are some of essential and nice-to-have portable GPS unit used for hiking and camping.

Map screen. Some handheld GPS devices can’t display maps at all; instead they provide your longitude and latitude, with a track of such coordinates to indicate where you’ve been. Other models let you load maps, and some can eve display downloaded satellite images. Screen displaying maps, not just a numerical lon/lat position, will make your life much easier.

Built-in basemap. Not absolutely essential, but highly recommended.

Water Submersible.Sooner or later your device will get wet. Your unit should be water submersible (waterproof standard IPX7) to protect it from getting damaged when it gets in the water. This means that is not just water-resistant, but that it can withstand accidental immersion in water for up to 30 minutes. Plastic bags and boxes are also recommended for added protection.

Large, easy-to-read display. Maps can be harder to read on the smaller screens that most handheld GPS models have, so I recommend that you choose a model with the largest screen size that you can see yourself carry. This is essential especially if you have problems reading fine detail. Color screen is cool, as it defines map features better than a black and white screen; backlight is also useful, although both features burn more battery power. Black and white screens are just fine for hiking and many color screens can be difficult to read in bright sunlight. So-called transreflective color screens may be your best choice: they are easy to read in direct sunlight and don’t use as much power with the screen backlight switched on. A screen protector is nice to prevent accidental scratches.

Compact and lightweight.  Here you will have to compromise between small size (recommended), so you don’t have to carry around a bulky device, and big screen size (also recommended), so you can read it without squinting. 

Power source and battery life. It is preferable to choose a portable handheld GPS unit that can support external power, such as a power cable or a cigarette lighter cable. Lithium batteries are recommended to ensure a longer battery life. It should use standard batteries (AA or AAA) for easy replacement on the trail, as always, rechargeable batteries are recommended.

Touchscreen or Rocker Keypad. Rocker Keypad designed for one-hand operation will make using your GPS device much easier. Some newer GPS units have touchscreens which helps immensely when navigating using the maps.

Channels. Most portable GPS units come with 12 channel parallel receiver system. Channels help receive satellite signals faster and more precisely. This is especially important in heavy tree cover or difficult terrain.

Memory. Lots of storage capacity (at least 20 MB)  is useful to upload detailed topographic maps, street maps, or additional waypoints. Higher end GPS handheld models accept a memory card for additional storage.

External amplified antenna. This is not a necessity, but may come in handy in places, where signals are weak.

Route capability and Waypoints. 20 Route capability is standard, some units have 50. 500+ user entered waypoints are pretty standard. Waypoints are specific geographic locations, described by longitude and latitude, that you have recorded in your GPS unit. When you press the waypoint record button on your GPS at a trailhead, you can always find your way back to your car. Cheap GPS handheld models will store relatively few waypoints; higher end units can store hundreds, and you can name them as you wish.

Tracks. As you go on your hiking trip, your GPS device records and displays a breadcrumb trail of where you’ve been. This process lets you easily backtrack to your starting point; some models also let you download your track to your PC and view your travels on a topographic map. You can print out the map and the track for a permanent record of your journey. As in the case of waypoints, low-end models offer limited track storage, while high-end models store many and allow you to identify them by adding custom names.

If you are thinking about buying portable GPS navigation system, read more on GPS Handheld Navigation blog, Choose the right handheld GPS device for your needs? If you are a golfer, you may be interested to learn how golf GPS systems can help you improve your game.