In brief: Basic map and compass navigation means reading symbols, scale and contours, orientating the map, following a bearing and checking distance. Resection uses bearings to identifiable landmarks to estimate your position. Practise these skills on straightforward ground before relying on them in poor visibility.
Most of us now carry a very good navigation tool in our pocket. Open a mapping app, find the blue dot and follow the line. It works brilliantly right up until the battery runs low, the phone gets wet, the maps you need haven't been downloaded or the route on the screen doesn't make much sense once you're standing on the ground.
That isn't an argument against GPS. I use it too. It is simply a good reason to understand the basics underneath it.
If you spend time walking, camping or travelling through unfamiliar country, you don't need to become a navigation expert. But being able to read a map, use a compass and work out roughly where you are gives you another option when technology isn't enough.
Start with the map, not the compass
A good topographic map is really a description of the ground. Roads, paths, rivers, woodland and buildings are useful, but the contour lines are what bring the landscape to life.
When the contours are close together, the ground is steep. When they spread out, the slope is gentler. With a little practice you begin to recognise ridges, valleys, summits, saddles and slopes before you ever set foot on them.
That changes the way you navigate. Instead of asking only, “Where am I?”, you start asking, “What should the ground around me look like?”
Orientate the map
One of the simplest habits is also one of the most useful: turn the map so it matches the landscape.
Use your compass to establish north, then rotate the map so the north-south grid lines line up with the real world. Once the map is orientated, features around you become much easier to recognise. A hill shown on your right should actually be on your right. A valley running away ahead of you should do the same on the map.
For accurate work, remember that grid north and magnetic north are not exactly the same thing. The correction varies by place and changes over time, so use the current information for your map and area rather than an old figure you happen to remember.
Taking and walking on a bearing
If you know where you are and want to travel towards a point that isn't joined by an obvious path, a bearing gives you a direction to follow.
Place the long edge of your compass between your position and your destination, with the direction-of-travel arrow pointing where you want to go. Rotate the compass housing until its orienting lines run parallel with the map's north-south grid lines, with the orienting arrow pointing towards grid north rather than south. Read the grid bearing, then apply the appropriate grid-to-magnetic correction.
Once you're ready to move, hold the compass level and turn your whole body until the magnetic needle lines up correctly with the orienting arrow. The direction-of-travel arrow now shows the direction of your bearing. Check that the ground along it is safe to cross; a bearing does not identify cliffs, deep water or other obstacles for you.
There is no need to stare at the compass while you walk. Pick a tree, rock, gatepost or another obvious object on the bearing and walk to that. Then check again and choose the next object. It is a simple way of keeping a straighter line.
Direction is only half the job
A bearing tells you which way to go. It doesn't tell you when to stop.
Distance can be estimated by time, pacing or a mixture of both. Neither method is perfect because steep ground, rough vegetation, bog, weather and tiredness all change your speed. Even a rough estimate is useful, though, especially when you combine it with what the map says you should see along the way.
Use the landscape to make navigation easier
Good navigation is rarely about marching across open ground on a compass bearing just because you can. Often the easier option is to use features that already exist.
A path, wall, stream, ridge or woodland edge can act as a handrail. Follow it and it does much of the navigation for you.
A catching feature is something obvious beyond your destination — perhaps a road, river or large track. If you reach it, you know you have gone too far.
An attack point is an unmistakable feature close to where you really want to be. Instead of trying to hit a tiny destination after a long crossing, navigate first to the obvious feature, then make the final short leg from there.
These are simple techniques, but they remove a lot of unnecessary uncertainty.
Resection: working out where you are
Resection sounds more technical than it is. The idea is straightforward: if you can identify known landmarks around you, you can use them to estimate your own position.
Choose two prominent features that you can identify confidently both on the ground and on the map. Take a bearing to the first one, convert it to the appropriate map bearing, then plot the reverse direction from that feature back towards your position.
Repeat the process with the second feature. Where the two lines cross is approximately where you are.
A third feature gives you a useful check. In practice, three lines often produce a small triangle rather than meeting perfectly at one point. That is normal; small errors in taking and plotting bearings add up. Treat that triangle as an indication of uncertainty, not proof that you are inside it. Check the result against contours and other features, and retake the bearings if it does not fit.
Keep track of where you are before you get lost
This is probably the most useful habit of all.
Don't walk for two hours without looking at the map and then suddenly try to work out where you are. Keep in touch with your position as you move.
If you cross a stream, find it on the map. If the path bends sharply, notice the bend. If you climb onto a ridge, identify it. If woodland should appear on your left after another kilometre, look for it.
It is much easier to know where you are continuously than to reconstruct your position after you have become thoroughly confused.
When something doesn't fit, stop
If the ground and the map stop agreeing, carrying on in the hope that something familiar will eventually appear usually makes the problem worse.
Stop and think back to the last place where you were certain of your position. How long have you been moving since then? Which direction did you travel? What features should you have crossed? What can you see now? Can you safely retrace your route?
Those questions turn “I think we're lost” into a problem you can actually work through.
GPS still has a place
Paper maps and compasses don't need to be treated as a protest against modern technology. GPS, offline mapping apps and dedicated navigation devices are extremely useful.
The point is to understand what the screen is telling you.
If your phone gives you a grid reference, you should be able to find that position on your map. If an app suggests a route, you should be able to glance at the contours and see whether that innocent-looking line crosses very steep ground or another obstacle.
The technology becomes more useful when you understand the landscape underneath it.
You only need the basics to start
Learn the common map symbols. Understand scale and contour lines. Practise orientating the map. Learn to take a bearing and walk on it. Get a feel for distance. Then try a simple resection somewhere safe where you already know your position and see how close you get.
None of it needs to be rushed.
After a while, something changes. A line of trees becomes a handrail. A church tower on the horizon becomes a useful position fix. The shape of a ridge tells you something before you even reach for the compass.
Your phone can tell you where you are. Knowing the basics of map and compass navigation means you also have a fair chance of working it out for yourself.
Map and compass questions
Do phone maps work without mobile signal?
A phone can obtain a satellite position without mobile reception, but the map itself needs to be available on the device. Download the area before leaving, check it offline and carry a paper map and compass you know how to use.
What is the difference between a bearing and resection?
A bearing gives a direction from one point towards another. Resection uses bearings to known features to help work out where you are. Both rely on correct landmark identification and the appropriate grid-to-magnetic conversion.