No love for the GPS?

In the classic “Ten Essentials” list published in the 1974 edition of Freedom of the Hills, two of the slots are reserved for a map and compass.  Modern versions bundle them into a single item under “navigation”, but the two are still considered the fundamental tools of wilderness navigation.  In the mountains an altimeter is also suggested.  Finally, a GPS device may be suggested as a supplement, often with warnings about the risks of electronics in the backcountry.

For the casual hiker this ordering of advice may cause more problems than it solves.  The reality is that as more people discover the outdoors, fewer of them can be expected to attain the same level of skills as those of yesteryear.  Being capable with a magnetic compass, a skill once considered fundamental, may soon be considered too much too hope for.  We are left with the less-savorable position of dealing with the world as it is, rather than the world as we would like it to be.

Comparisons between a GPS device and a magnetic compass usually focus on a few elements:  the risk of damage or failure of the electronics, running out of batteries, and unreliability in canyons or dense vegetation.  Conversely, a magnetic compass is often presented as inherently reliable, works everywhere, and doesn’t need batteries.  While the reliance on batteries is undeniable, it is easily mitigated.  As to the remaining criticisms, the vulnerability of the simple compass to similar criticisms is often unappreciated.

In this post I’ll argue the position that instead of “map and compass”, a default recommendation of “map and GPS” would better serve the average hiker.  The learning effort required to use a GPS device effectively is quite minimal, and having one usually eliminates the fundamental problem of being lost: not knowing where you are.  Additionally, nearly everyone is already carrying a GPS-capable device on them, but few know how to take advantage of this.  Finally, I’ll mention a few of the reliability issues with compasses and point out battery management, or carrying spares, is not particularly difficult these days.

My argument…

The magnetic compass is an ancient device.  For a lost hiker, it’s very likely they will not be able to use it to become found.  Such techniques exist, but rely on the presence of distinctive nearby landmarks that the user recognizes.  (In which case, it would be hard to argue that they are lost.)

There does exist a use for the compass in a whiteout, but it must be carefully paired with traveling skills, as one may still find their path diverted into a counterproductive spiral.

Getting off on the right foot…

To begin I’ll suggest a few guidelines on using your device effectively.  They may differ from how you expect to use a GPS, but they’ll put you far ahead of the curve when it comes to actual navigation.

  1. If you’re not flying or floating, don’t use degrees.
  2. Your paper map is your best map.
  3. Don’t play “follow the arrow.”
  4. Put your phone in airplane mode.

Obviously these guidelines leave plenty unsaid, but they’ll keep your locations accurate, your brain on task, and your batteries alive.

The first item eliminates a significant cause of error in communicating coordinates, and also allows you to nearly instantly translate your coordinates into a location on your paper map.  The second further encourages this, by leveraging the comparatively massive screen size of a paper map compared to a miniature electronic screen.  I have yet to see an effective map display on the hand-held GPS unit.

The third item is literally to keep your brain’s navigation ability from atrophying.  If you just follow what the device indicates is the correct direction, your brain won’t bother constructing a spatial map of the area.  Do that long enough and your hippocampus may slowly atrophy, which is no fun at all!

Finally, the last item is just common sense; if you don’t have a cell signal your phone will scream its little heart out searching for one, leaving you with a drained battery and a useless device.  If you regularly find your phone running low on power, perhaps you shouldn’t use it for navigation.

So, how does one go about using a map and GPS?

From the first guideline, use a grid system.  Pretty much everyone knows how to use a grid to find locations; you have an x and a y coordinate and the spot is where the lines meet.  Set your device’s display to USNG (or UTM) and take note of the displayed coordinates.  Now, from the second guideline, look at your paper map.  Most any quality topo map these days has a UTM grid on it.   Find those numbers along the map borders and compare them to the coordinates on your device.  Simple, no?

This is a bit like going metric:  there are all sorts of useful benefits, but support in the US can be… lacking.  Google Maps appears to have finally added support for USNG values when entered in the following format: 10SFG 26050 56050.  UTM values still appear unsupported.  Many groups are still used to working with UTM, but the federal standard for land-based SAR is USNG, and I personally feel the benefits make it worth the switch.

Back in 2010, Michael Coyle wrote “In the past 10 years, the biggest errors in navigation I’ve seen have all been variations on transcription errors.”  There are numerous ways to write down degree-based coordinates, and thus numerous ways to misinterpret them.  UTM avoids much of this, but still includes a few too many digits for my taste.

Now, with your map and GPS in hand, you can be dropped into any random spot on your map and you’ll be able to tell where you are.  You’ve likely also determined that you can tell which way you’re going by watching the numbers move, and the sharper among you will have noted that the numbers represent distances in meters.  I may be optimistic, but I’m guessing you’d be able to find your way back to your car or a nearby road as well.

How do you get a good map?

Assuming you don’t have a good map already in hand, I suggest wandering over to CalTopo and printing one out.  I’m partial to the USGS and the USFS map layers depending on location, and I make sure to check the box to include grid lines.

Do you need to purchase a GPS device?

In most cases the answer would be “no, you already have one in your phone”.  I do own a handheld device, but I don’t regularly bring it on hikes; it’s overkill for that.  Modern phones contain a GPS chip that is sufficiently accurate for most wilderness use.  (The main risk is running out of battery or shattering the screen.)  What you will need to obtain is an app that can display your coordinates in a reasonable format.  The cheapest option I can think of is going to the website, which should then save itself into your phone’s application cache for offline use.  This isn’t as durable as a dedicated app like Gaia GPS or OruxMaps, as device updates might clear the cache, but it’s a “bare minimum” that you can ask everyone in a group hiking trip to visit and bookmark while they still have signal.

Regarding dropped phones, the most I can say is to get a good protective case and only pull out your phone when you’re safely stopped and sitting down.  There’s no need to be running through the woods, phone in hand, as you watch the numbers change.  If you tend to be clumsy, it might be a good idea to get a basic handheld GPS after all.

How reliable are magnetic compasses?

Ask most people this question and they’ll likely answer “very!”.  There’s only one moving part and no batteries to run out.  It is also true that dropping one is unlikely to cause sufficient damage to render the device useless.  (Although, it might develop a bubble.)  So, time to discuss issues.

The magnetic compass works by aligning itself to the local magnetic field.  In the absence of local distortion (your vehicle, a metal canteen, a rifle, or even a heavy steel watchband) this will usually align with the local magnetic north.  In some places this might align with true north, but usually not.  Your map should have a small diagram indicating the direction of magnetic north for the area.  Use a recent map, because that direction changes over the years.

Things get more interesting when local distortion is present.  Interference from nearby metal objects can throw your compass off by at least 3-4 degrees, and if you’re in an area with significant ore deposits your compass could be off by almost any amount.

What’s more problematic is that it’s possible to reverse the polarity of a compass needle, so that it permanently points south instead of north, or even off to one side.  A rather dramatic example can be seen at  If you want to read more about this phenomenon there’s a short write-up at, but the takeaway should be to test your compass before any trips, and don’t store it alongside electronics (such as in the same pocket as your phone, or around your neck when your phone is in a chest pocket).

Does this mean don’t bring a compass?

Certainly not!  A compass is particularly useful when you want to make sure the direction you’re walking is the direction you think you’re walking.  It can also be used in some cases to figure out your location, although with some degree of error and a very large dependence on distinctive landmarks.  Both of these uses require developing some small amount of skill, and unfortunately the purpose of this post is to acknowledge that such development may be too much to hope for.  My hope is that by encouraging more accessible alternatives, more people may be able to keep themselves found.