It’s a few years old now, and never received the best reviews, but many users have been very satisfied with their Bushnell Onix 400 Weather Tracker GPS.  Now discontinued, this GPS handheld that once cost over $500 is now available for under $80 on Amazon and Ebay, making it the hiking GPS deal of the week.

This unit attracted notice when first released because of its unique feature set, combining standard handheld GPS navigator capabilities with XM weather data and the ability to display satellite photos.

The subscription XM satellite radio feature also provides basic news, sports and music programing. The weather display gives users local forecasts, and allows them to display weather maps including radar as a layer on  top of navigational maps.

In its waterproof rubber case the unit is rugged enough for heavy outdoor use, but some users have found it overly large and clunky. But the 11-ounce package delivers strong GPS functionality with a 3.5 inch color screen, SiRFstar III antenna, and 128 megabyte memory with 20 routes and 1000 waypoints.

The Bushnell Onix 400 was never going to match the elegance of a Garmin Oregon. But especially if you like the Weather Tracker feature this is a great GPS bargain for under $100; who knows how long they will last at this price.

There are pros and cons to backpacking with a GPS. Traditionalists who take pride in their skills with map and compass may want nothing to do with satellite-enabled navigation. For some people, entering the wilderness means leaving all the trappings of modern life behind–the last thing they may want to carry with them is an electronic gadget with a screen. On the other hand, a backpacking gps can bring an added dimension of fun, utility and safety to your backcountry trip. (Safety-wise, it should go without saying that you should always have a map and know how to read to compass, GPS or not!)

If you are a backpacker contemplating buying a handheld gps unit for the first time, you can narrow down the possibilities by asking three basic questions. First: do you want a device that will show your actual topographic map location on the screen? If so, you want a mapping GPS capable of uploading and storing detailed topo maps such as those available from Garmin Mapsource or the National Geographic Topo series.  These kinds of devices will let you a plot a mapped course in advance, and follow it to your destination.

Now if you’ve never used a GPS before you may be wondering, what’s the alternative? Well, a non-mapping GPS of course! Graphically rendered maps are in fact relatively new in the GPS world. The basic GPS functionality is not mapping but positioning, and this is what you get with non-mapping devices: your actual location in terms of latitude and longitude. So don’t throw out those USGS topos, you’ll still need them to see where you are if you choose a non-mapping unit.  But you don’t just get a set of coordinates: These devices will also let you set waypoints, or locations you want to be able to find your way back to. And most will show a “breadcrumb trail” of your journey from starting point to wherever you are. With that in hand, you still may not know where you are, but you won’t be entirely lost either.

OK, question two. This one is about your backcountry philosophy. Are you of the ultra-light, minimalist persuasion? Or are you the sort who is happy to carry 15 pounds of extra gear, optics, field guides, or whatever into the wilderness, because it’s fun to have? If going light is priority number one, you might want to consider a small, non-mapping GPS  locator, or even a GPS watch.  Be mindful however that there can be an inverse relationship between size and simplicity, or ease of use. A hiking GPS device with tiny buttons or multiple features requiring special key sequences can be frustrating to use, particularly when your hands are cold.

If a few extra ounces are not a concern, that leaves open the full range of possibilities. There’s really not a huge difference in terms of weight between a 2 ounce wrist GPS and a 7 or 8 ounce full feature unit like a Garmin Oregon.  But for ultralight enthusiasts every ounce counts. And keep in mind batteries, as a function of weight. For a device to function for the duration of your trip, will you need to take along extra batteries? If so that’s a heavier unit than one that won’t need a recharge.

The final question is how much you want to spend. As you can probably guess, there’s a fair amount of correlation here among all three questions: non-mapping units tend to be smaller and lighter, and generally cost less. But particularly within each of the broad categories (map or non-map) cost is a real factor. You can spend under $200 or over $500 for a good handheld GPS well-suited to hiking and backpacking. The extra dollars can get you higher quality and a better set of features, but watch out for paying extra for things you really don’t need or want. (Do you really need to take photos with your GPS?)

For hikers and backpackers there are several features worth considering paying a bit extra for. Devices with a high-sensitivity processor chip such as the SiRF Star III are the most accurate and, even more importantly, the most sensitive. That means the receivers can often pick up a signal in a deep canyon or through a dense tree canopy.  Make sure your device has a quad helix antenna structure as well, for best reception under tree cover.

Adaptability is also nice. You can do more with units that have more memory, and that can easily load and store map data. Make sure you are getting a device that can store a sufficient number of routes and waypoints to suit your needs. A laptop interface is essential, with the ability to upload data from CD map collections. Having the ability to install maps on pre-loaded memory cards is even better. Some units even come with complete topographic map series for North America pre-installed.

Finally, if you are purchasing a mapping GPS pay attention to the screen size and brightness. Keep in mind that viewing conditions vary, and certainly will not always be the way they are in the store. You want something you can actually read while crossing a snow field above timberline.

These are the basic factors to consider when selecting a hiking or backpacking GPS receiver. In my next post I’ll flesh this out with some specific examples and recommendations in each of the categories discussed here.

Whether you are into hiking,  bicycling, hunting or boating, a portable handheld GPS can be a great asset in the outdoors.  For some people using GPS for navigation is an important part of the fun associated with an outdoor experience. Others may simply want a reliable substitute for paper topographic maps–or simply some insurance that they can find their way back home! Regardless of your outdoor interests, it’s not hard to find a good hiking GPS to match your needs and your budget.

We’ll begin with a broad overview of the kinds of devices available, and what features you may want to look for. An important distinction in handheld gps devices is between mapping and non-mapping units. Mapping GPS receivers display your position on a map that may include roads, trails and natural landmarks. Non-mapping devices provide directional information and let you plot your course with position-marking waypoints, and then retrace your route using a simple plotter screen but no underlying base map.

The simplest and least expensive non-mapping devices are personal trackers or locators, such as the Bushnell Backtrack series. Just set your starting point with one of these devices, and no matter how far or long you wander you will always know which way is home. However on the least expensive models, the number of waypoints that you can set is limited.  The next step up for non-mapping GPS takes you to the lower end of the Garmin eTrex and Geko series. These types of units can often be found for under $100, and support a broader array of routing options with 500 waypoints.

But what if you want to find your way to some desired destination, such as a remote campsite or mountain lake? For this you may want a GPS device with maps loaded that can show you where you are, relative to your destination, so that you can choose the best route. Obviously this will require good maps in addition to a GPS unit capable of displaying them. Both Garmin and National Geographic produce topographic maps for GPS devices, but make sure you actually have the level of detail you need before hitting the trail.

Mapping handheld GPS navigators begin with relatively simple units like the Garmin eTrex Legend and Vista. These units comes with (rather limited ) preloaded base maps and includes internal memory for uploading and storing additional maps.  Slightly higher-priced units like the Garmin eTrex Vista, Venture and Summit HC GPS navigators provide more memory–which you probably want if you plan to upload topographic maps–and some allow use of an SD card for loading and storing map data, including complicated routing information with large numbers of waypoints.

There are many variations among these models, but in general you can expect newer and more expensive units to come with better pre-loaded base maps and other improvements.  Any of the mid- to upper-range eTrex handhelds  are good if you want to load topographic map files individually, but don’t require huge amounts of data storage. These navigators have more sensitive receivers than baseline models, and come with a larger color screen. They also add additional features, including compass and altimeter, and often a rugged waterproof case for heavy outdoor use.

Hiking GPS units with pre-loaded topographic maps include the popular Garmin Oregon and Colorado series. A number of different versions are available, most with bright easy-to-read screens and 3D rendering of map data. Top of the line units add a range of other features including built-in cameras that automatically geo-tag photos. Another great option that comes with topographic maps is the Delorme Earthmate PN-40, or the newer and considerably more expensive PN-60.

Outdoor GPS users have dozens of options, and this review barely scratches the surface in terms of models and features available. Watch this site for individual hiking GPS reviews and ratings, and more detailed discussions of what features matter most in a handheld navigator.