racks, routes, waypoints, GNSS, topo, GPX, inReach...what does it all mean and do you really need to care? Just like every other aspect of adventure, you can’t be sure you need to know something until you know it. Catch 22.

Adventure Monkey to the rescue! We’ll define the 7 terms you need to know to navigate your next adventure, and tell you how much you should care.

BTW, we define and use these terms in the context of digital navigation, like when you use a GPS device or a phone app. We’ll cover analog paper-based navigation in a separate article.

The 7 Terms You Need To Know for Off-Road Navigation

1 - GNSS

“What GPS watch should I get?” “What GPS should I use for hiking?” “What’s the best GPS app for off-roading?”

We use “GPS” as shorthand for satellite-based location finding and navigation, but GPS is actually just one of many Global Navigation Satellite Systems, or GNSSs.

What Does GNSS Really Mean?

A GNSS is a constellation of satellites (at least a couple dozen if you want global coverage) that hang out in orbit around the Earth. They each constantly broadcast their location and the current time using their super-accurate atomic clocks.

Your GNSS receiver (watch, handheld, phone, tablet, etc.) receives those radio frequencies from at least four satellites and then does some math to determine your location and altitude.

Launching and maintaining a global constellation of navigation satellites is of course crazy expensive, which is why only governments have done it. (Though don’t put it past Elon to create a SpaceX version someday.)

There are four GNSSs:

  • Global Positioning System (GPS) - United States
  • Galileo - European Union
  • GLONASS - Russia
  • BeiDou (BDS) - China

GNSS receivers listen for the broadcasts from one or more of these GNSSs, for example:

Receiving signals from all four GNSSs. It's like the United Nations of navigation.

What Can Understanding GNSSs Do for Me?

If you want to really understand how GPS and the other GNSSs work, read our article What Is GPS and How Does It Work?

But for your everyday needs, just understand that using a GPS receiver that can receive signals from multiple GNSSs will yield a more accurate position, within reason and depending on a ton of other factors, like urban vs rural and forest vs desert. Though it’s not like receiving all four will tell you whether or not you’re standing on a specific pebble.

Nearly every phone, tablet, watch, handheld and vehicle-based device will receive GPS, so when you’re shopping, look for GPS + as many others as possible. That being said, don’t fret too much if the watch you want is only GPS + Galileo instead of GPS, Galileo and GLONASS. It’s not THAT big of a deal.

Here are a few devices capable of receiving transmissions from multiple GNSSs simultaneously:

2 - Topo Maps

The most difficult thing about navigating off-road is that everything on your Garmin or phone looks so flat and the real world just...isn’t.

This challenge of accurately converting our 3D world into a 2D map is one that has plagued mankind since we first drew lines in the dirt with sticks.

The mercator projection map - solution to the problem of making a sphere flat in the year 1569.

For example, Wikipedia can tell you Imogene Pass in Colorado is at 13,114 feet (3,997 m) elevation. But what would be a LOT more helpful is to know how steep the road up the pass is, from Ouray all the way up. This is what topo maps do for you.

What Is a Topo (or “Topographic”) Map?

A topographic map is a type of map that uses elevation contour lines to show in 2D the shape of our 3D planet. This makes it possible to visualize the height and shape of mountains, as well as the steepness of slopes.

This is obviously pretty valuable info to have at hand, so you’ll find topo maps everywhere: GPS devices, mapping and navigation apps...even good ol’ paper!

How Do You Read a Topo Map for Off-Road Navigation?

Let’s do a quick visual. Since we were talking about Imogene Pass, here it is from Google Maps satellite view:

I don't know, doesn't look that bad to me.

And here it is on a topo map:

Yikes! What is all that??!?

Here’s what the lines mean. Picture yourself out on a flat road. You’re standing at a particular elevation and if you walk a ways down the road, you’re still at the same elevation since it’s flat. If you draw a line between your starting and stopping points, you would know that every spot on that line is at the same elevation.

Those brownish lines in the topo map do exactly that; they connect all the points that are at the same elevation.

On the map above, look up and a little to the right of Telluride Peak. You’ll see “13200” in brown, right on a thick line, telling you that line is at 13,200 feet. This line is called a “contour line,” and every spot on that line is also at 13,200 feet. (This explains why they’re wavy, because they’re tracing exact elevations through valleys, over peaks, around water and so on.)

Every fifth contour line in the map is thicker and shows its elevation somewhere along it. On this map, 200 feet of elevation separate the thick lines, with four thinner lines in between, which means that this map has 40-foot contour intervals. Walking from a spot on one line to a spot on the next will put you 40 feet higher or lower than where you started.

This is how you determine the shape of the terrain and the steepness of the slopes. If you’re driving up a hill and the contour lines are really far apart, it’s a pretty shallow incline. If those lines are crowding up against each other, you better make sure you’re in 4WD Low!

What Can Reading Topo Maps Do for Me?

Learning how to read and effectively use topo maps is critical for your fun, safety and success, so we’ll be covering them in great depth in a future article.

But in the meantime, make sure you are downloading and using topo maps on your GPS devices so you can get used to them. Whether you’re hiking, overlanding, adventure riding, canoeing or anything else, have the topo map active on your GPS and compare what you’re seeing around you to how it’s represented on the map.

We’ll leave you with some tips:

  • Remember, the closer the contour lines are together, the steeper the slope. If the lines are REALLY close together, we call that a cliff. Stay away unless your adventure involves rock climbing.
  • The lines indicate the shape of the terrain, so if you see concentric circles, you’re looking at a hill. Low areas between two hills are called “saddles.” You might be able to avoid summiting a hill by passing through the saddle, but it’s not necessarily a good plan. Gotta read the whole map!
  • The distance between contour lines varies from map to map (typically 40 or 80 feet though). But the distance is always the same on a map.
  • Map scales (not just topo maps) are written like 1:24000. You read that as 1 unit of distance on the map (cm, inch, doesn’t matter)  is equal to 24,000 of the same unit in the real world. The larger the scale (e.g., 1:65000), the more in-real-life area it covers but the less detail it can show.

3 - Waypoints

Say you’re hiking and find that perfect, secluded spot right by the lake that you’d love to return to next time. Or you’re planning a Jeep drive and see a neat little valley on your map that would be a great day-trip destination. How do you mark these things in your GPS so you don’t lose them?

You save them as waypoints.

What Is a Waypoint?

A waypoint is simply a location that is stored in your GPS receiver, usually as a set of coordinates. You actually use waypoints all the time without knowing it. If you Google “barbecue near me,” the pin on the map is a waypoint. Similarly, points of interest (POIs) in your GPS are pre-loaded waypoints.

(Technically, waypoints are not exclusive to digital navigation and, like most modern electronic navigational concepts, date back as long as humans have traveled. You can use “waypoint” whether you’re talking about truck GPS navigation or lacing up to go on walkabout.)

Each waypoint is unique and you can name it or it’ll have a pre-generated name when you save it. Just about any GPS device will let you place a waypoint manually, either by setting it where you are at that moment (e.g., trailhead) or in some other spot on the map after some panning/zooming around. You can also mark them in desktop mapping software when you’re planning your adventure.

What Can Waypoints Do for Me?

There’s really no limit to their usefulness and you should get in the habit of saving waypoints if you think there’s even the slightest chance you’ll want to know where that specific location is again. They can help you in myriad ways:

  • You mark the trailhead (or where you parked your car) when you start your hike so you can easily navigate back to it.
  • You’re following a track on your GPS (see “tracks” below) and the junction is nearly impossible to see so you mark it explicitly for next time.
  • You find a great camping spot overlooking the lake and want to share it on iOverlander.
  • You’re meeting up with some friends to go adventure riding so you agree on a meetup spot.
  • They could even be locations to avoid, like an area of deep sand you don’t feel like getting stuck in again.

Basically, ask yourself, “Is this a location I want to remember?”

Once you get into the habit of marking waypoints, you’ll create quite a collection, so here are a few tips:

  • Plan for a future where you have a ton of waypoints stored, so start using prefixes, like for an area (“GC-” for Grand Canyon trails) or type of activity (“KAY-” for kayaking spots).
  • Don’t store them all just on your GPS. Use mapping software and keep everything both synced and backed up.
  • If you’re planning your route or stops in advance with waypoints in your mapping software, they’re going to be a bit off, accuracy-wise. When you get there, reposition them to where they should have been.
  • When you want to ensure a waypoint is as accurately positioned as possible, use waypoint averaging if your GPS has it. It will take a number of GPS positions over a period of time and then average them to (hopefully) get a more accurate position.

4 - Routes

You’re planning an adventure trip this weekend and you start by placing waypoints in cool spots in your mapping app of choice. You have the camping spots picked out, the lake you’re going to paddle board and the overlook you want to hit on the way back. String those waypoints together and you have a route. Time to head out!

What Is a Route?

A route is a path that you pre-define, consisting of a series of waypoints or points of interest (which, as we now know, are technically waypoints too). A route is usually used for navigation and it’s really easy to add or remove waypoints along the way.

We’ll discuss tracks in the next section and how they compare, but routes are best suited when you want to reach a particular destination, without care as to how. Your standard turn-by-turn directions in Google Maps are routes. Find the barbecue joint you want to hit and then leave the actual route planning to Google.

What Can Routes Do for Me?

They’ll get you where you want to go. Want to take the truck to the backside of that lake? Turn on your Garmin or open a nav app, drop a pin and see if it can find the road to get you there. Fancy a hike to the natural bridge your buddy told you about? Drop a pin and follow the route. Rolling through town in all your overlanding glory but secretly you’re looking for a real shower? Pick a hotel and...well, this is essentially Google Maps and you know how to do it, but it’s a route.

Couple items to note. If you go off the route, your GPS will recalculate the path to follow, which may not be along the exact path you had planned. We’re used to Google Maps or Apple Maps rerouting us like this, but when you’re off road and you were looking forward to following a particular trail, this rerouting can screw up your trip if you’re not paying attention.

Also, watch out because the route will often default to “as the crow flies,” which means you yourself may need to be able to fly if you’re to get from one waypoint to another.

I'm not sure even a crow can fly that distance and your Jeep surely can't.
That seems MUCH more doable.

How routing works depends on the GPS device, the navigation settings, the map and how off-road you’re planning to travel since not all trails are routable.

Here are a few more “route” tips:

  • Sometimes you’ll miss a waypoint or put it in a screwy spot that’s impossible to get to (don’t ask us how we know this). Depending on the device, it may automatically route to the next waypoint or be really insistent that you go back to the missed one, with the distance growing as you leave it behind. Sometimes it resolves itself as you get closer to the next waypoint, but sometimes you have to manually delete the missed one or select the new one.
  • The span or distance between two points in a route is called a “leg.” Use this in a sentence and impress your friends.
  • Most GPS devices let you reverse a route. This is useful if you’re planning an out-and-back.
  • Make sure you drop waypoints while on your route, whether for interest or safety.

5 - Tracks

Routes will get you to a location of your choice when you don’t care how you get there. But what if you do care? Then you need a track.

What Is a Track?

A track (aka “tracklog”) is a series of track points. Note that these are not waypoints or points of interest. I guess they could be, but in practice they’re not because tracks are an after-the-fact series, as opposed to routes, which are before-the-fact.

Let’s back up. As we just learned, routes are created before you head out on your adventure and you necessarily have to at least know your destination.

Tracks though are created while you’re on your adventure. When you head out, you start tracking your location and then stop the tracking when you reach your destination. They’re sort of like breadcrumbs that you drop along the way. If you want, you can go back and follow the breadcrumbs again and you’ll experience the exact same journey.

If only Hansel and Gretel had a GPS.

So, unlike routes, tracks are what you need when you want to follow a very specific path to your destination. Also, unlike routes, if you go off track, your GPS will direct you back to the track itself, not the waypoint you missed or the next one. (If it directs you at all. Oftentimes tracks cannot be used for turn-by-turn directions like routes can.)

But wait, if tracks are created while you’re blazing your trail, how can you follow one when you’re navigating off-road?

The answer is that tracks can be saved and reloaded for future use. You can also follow a track that someone else created. These files are shared on the interwebs, which is nice for finding new adventures.

The Arizona Backcountry Discovery Route, which can be downloaded as a track to follow exactly. Perhaps not “exactly,” since your skills may not match theirs. Screenshot from ridebdr.com.

What Can Tracks Do for Me?

If you think of tracks as the actual path you (or someone else) took, you’ll begin to appreciate their value. When a buddy says, “Oh man, we drove this trail that went right along the ridge and the views were insane. I’ve never felt closer to Heaven,” you want that exact trail, every turn. You want his track.

Always track your drives, hikes, sailing trips, motorcycle adventures, everything. Worst case scenario, it was a bum trip and you delete the track, never to retrace your steps. Best case scenario, you share your track on your forum or subreddit of choice and become a legend.

Some track tips:

  • Most devices have a trackback (or “TracBack'' for you Garminers) feature that reverses the track you’ve been recording. Some people use this feature to do an out-and-back, but we’ve never been fans of that. We’d rather plan the entire out-and-back as a route so you get all the stats (time, ETA, distance, elevation changes, etc.) for the full trip, rather than treating it as two halves. But reversing the track can be a lifesaver if, for example, you get stuck, lost or caught in a whiteout. Just reverse the track and get back home. Another reason to always be trackin’.
  • When you’re recording your tracks, you’ll set an interval. This is a set time or distance between track points and you should ensure you set a sensible interval. After all, there’s no need to chew up battery and storage by logging a track point every two seconds if you’re just going for a leisurely hike. In contrast, if you’re banging through the desert in your side-by-side with 10-minute tracking intervals, your tracklog will be missing a lot of turns and curves.
  • Tracks can be saved and synched back to your computer to be backed up, reused, traded or even visualized on Google Earth. We’ll be doing an article on this one for sure.
  • You can find a ton of tracks online for any activity you’re into. They’re usually in the form of a .gpx file.

What a segue!

6 - GPX Files

When you want to save, share or upload a track (or “tracklog”), you’ll more than likely be using a .gpx file, which is commonly written as GPX. (There are other file types for GPS coordinates and location details, such as KML (.kml), which Google likes to use. But GPX is the one you’ll see most frequently.)
What Is a GPX File?

A GPX file is a standardized file format for GPS tracks, like .docx is a file format for Word docs. If you want to get geeky, .gpx is an XML schema.
Location data (and, optionally, elevation, time and other info) is stored in tags, which are read by the GPS device and converted into the waypoints, tracks and so forth. Having all that data encapsulated in a single file is what enables the sharing.

As an XML file, GPX files are actually pretty easy to read and the tags are descriptive of what comes between them. Here’s a snippet of the actual GPX file that you can download for free from the Backroad Discovery Routes site.

These are the actual track points in a GPX file. If you follow these points, you'll be following the Arizona BDR.

If you go to their site and zoom in on the map of the BDR track, you’ll see a number of waypoints that they’ve also thoughtfully recorded so you can stop for fuel, views, camping and more. These waypoints are also in the GPX file:

GPX files also show waypoints, or points of interest. File also from the Arizona BDR.

One thing to note is that since those files are XML schema, you can delete or add track points or waypoints directly within the file, if you know what you’re doing or feeling frisky. Just make sure you add or delete the entire element block. For example, if you don’t want Aztec Peak to show on your map in the above GPX snippet, delete that entire element block: <wpt...> through </wpt>.

What Can GPX Files Do for Me?

The coolest thing about GPX files is that, since it’s a standardized format, just about any GPS device can read them and load them for you to follow. The importing of the files can sometimes be quite laborious and confusing, and it differs between manufacturers and even between devices from the same manufacturer (*cough* Garmin *cough*). We’ll have some how-tos coming for the top devices and apps since this is a key component of any off-road adventure.

The benefits are not just from taking advantage of the scout work of others, but also the tracking and saving of your own adventures to view on a map later or to retrace on a future trip. And if you blaze a cool trail of your own, you can upload the file into the forum or subreddit of your choice and score some grateful emojis.

Where Can I Find GPX Files?

Oh man, all over the place. There are a lot of paid apps and sites that have great trails, but there are also a lot of free resources. Here are a few to whet your appetite:

  • Any adventure-oriented forum worth joining will have GPX files being shared by their members. Go to your favorite and search “GPX” to see what comes up, or ask the members if they have tracks to share in the geography you want to explore.
  • Backcountry Discovery Routes - BDRs are scouted by the team to find the best off-road journey each state or region has to offer. Their routes aren’t always the gnarliest trails, nor are they the easiest, but they always give you great views, great adventures and a great taste of that part of the country. Don’t let the motorcycle-centric feel of the site dissuade you from tackling a BDR with four wheels as most are quite doable by ATV, SxS, Jeep, truck or anything short of an EarthRoamer.
  • There are also sites specifically for sharing trails. A great example for hikers is AllTrails. You don’t have to use their map...just sign up for a free account to download tracks other hikers have uploaded.
  • If you prefer wheels over walking, Trails Offroad has a great collection of trails, downloadable after a free signup. Also check out Jeep the USA and challenge yourself and your rig. And despite the name, you can drive whatever you want on the trails, they won’t check.
  • There are global sources too, so if you live outside America or are adventuring abroad, a little creative googling and forum hunting will reward you with the GPX trails you need. For example, if you’re in Europe, check out the Trans Euro Trail and journey from Africa to the Arctic Circle. Sand to snow in one trip.
  • Finally, ask your buddies!

7 - inReach

This one’s a bit of a cheat for this list because it doesn’t have anything to do with truck gps navigation or any other form of navigation. But a lot of people think it does, so we’re going to do our part to eliminate the confusion.

What Is inReach?

inReach is actually a registered trademark of Garmin’s and they use it as a feature name for the satellite communication capabilities of their devices that have it.

The broader category that inReach devices play in is satellite communicators, aka satellite messengers. Not to be confused with satellite phones, these devices allow for text-based communication via satellites. (The even broader category would be satellite locators, which would also include personal locator beacons (PLBs), but these are mostly limited to SOS functions, not communication, so we’re ignoring them for now.)

Satellite communicators aren’t actually involved with navigation at all, but they’re often lumped in with GPS devices because

  1. they also use satellites, though not the same ones, which is confusing, and
  2. Garmin integrates their inReach capabilities with a number of their handhelds and markets them aggressively, so the terms get conflated.

Shockingly, Garmin’s not the only manufacturer of satellite communicators and you’ll come across Spot, Bivy and a handful of others. That being said, we use “inReach” as a generic term for satellite communicators a lot in this section since it’s a well-known brand and, you know, shorter to type.

What Can inReach Do for Me?

If inReach-enabled devices don’t improve my navigational duties, then what good are they? They primarily serve two functions.

First, they let you call for help, even if you’re waaaay off grid. inReach uses the Iridium satellite network, which consists of 66 low Earth orbit (LEO) satellites that cover 100% of the planet. Hit the SOS button on an inReach device and within minutes you’ll be texting with a service center that will figure out exactly what help you need and get it dispatched.

Second, they let you communicate and share with family and friends while you’re on your adventure. You can text directly with folks along the way, whether to make them jealous or to let them know you’re having so much fun you’re never coming back.

And it’s not just typed-out thoughts that you can send. You can also share your location and tracks via those satellites so folks can see where you are. (It helps to remember when you have tracking active since some satellite communicators show your location on a map when friends track you. We’ve been surprised by inReach texts from friends asking how far the stream is from our tents while we’re in the middle of the forest!)

Satellite communicators have other features that can be extraordinarily useful, depending on your adventure. For example, Garmin’s inReach devices can pull down hyper-localized weather forecasts, so if you’re on a thru-hike and wondering what those dark clouds on the horizon have planned for you, this could literally be a lifesaver.

inReach and other devices work in a way similar to buying a new phone. You first buy the device and then you sign up for a subscription service. And just like a phone, if you don’t pay for a subscription, your inReach can do some things, but nothing you really want it to do.

Fair warning: signing up for a plan is an incredibly opaque and confusing process, but the subscription options essentially come down to how frequently you think you’ll be using the thing for location tracking. Rather than go into it here, we’ll cover satellite communicators and subscription plans in separate articles in the future.

A few satellite communicators to check out are:

Adventure Monkey Summary

So there you have it, the 7 terms you need to know for off-road navigation. Okay, there are a lot more terms you’ll need to understand to really get your money’s worth out of your GPS device. But these seven are so frequently used and so infrequently explained that you’ll now better understand the more esoteric terms, concepts and explanations that you run into.

We have a lot of great reviews and how-to navigation articles and videos coming to help you know what to buy and how to use it to experience an off-road adventure so spectacular, so fun-filled and so unique that everyone will be begging you to share your tracks. Via GPX file, of course.

Feb 13, 2021

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