Why Traditional Navigation Still Matters
In an age of GPS-enabled smartphones and dedicated navigation devices, it's tempting to assume paper maps and compasses are relics. They're not. Electronics fail at the worst possible moments — dead batteries, broken screens, signal loss in deep canyons or dense forest. Every competent backcountry adventurer should be able to navigate using a topographic map and a baseplate compass as their primary skill, with digital tools as a useful supplement.
Understanding Topographic Maps
A topographic map represents three-dimensional terrain on a two-dimensional surface. The key elements to understand:
Contour Lines
Contour lines connect points of equal elevation. The closer the lines, the steeper the terrain. A series of closed concentric circles indicates a peak or hilltop. A V-shape pointing uphill indicates a valley or drainage; a V-shape pointing downhill indicates a ridge spur.
Contour Interval
This is the elevation difference between each contour line, shown in the map legend. A map with a 20 m contour interval means each line represents 20 m of elevation change. Count the lines between two points to calculate total ascent or descent.
Map Scale
Scale is expressed as a ratio (e.g., 1:25,000). This means 1 cm on the map equals 25,000 cm (250 m) on the ground. For serious backcountry navigation, 1:25,000 or 1:50,000 scale maps are the most useful.
Grid References
Most topographic maps use a grid system. An 8-figure grid reference pinpoints a location to within 10 m — precise enough for most navigation needs. Practice reading and giving grid references until it becomes instinctive.
Using a Baseplate Compass
A quality baseplate compass (such as those made by Suunto or Silva) has several key components:
- Baseplate: The flat transparent base with direction-of-travel arrow
- Rotating bezel: Marked in degrees 0–360
- Magnetic needle: Red end always points to magnetic north
- Orienting arrow and lines: Inside the bezel, used to align with the map
Taking a Bearing from a Map
- Place the compass on the map with one edge running from your current location to your destination.
- Rotate the bezel until the orienting lines inside align with the north-south grid lines on the map (north arrow pointing to top of map).
- Read the bearing at the index line — this is your magnetic bearing after applying declination.
- Declination: The difference between true north (map north) and magnetic north varies by location. Check the map's legend for local declination and adjust your bearing accordingly — this is a critical and commonly overlooked step.
Walking on a Bearing
- Hold the compass flat in front of you with the direction-of-travel arrow pointing away from you.
- Rotate your body until the red needle aligns with the orienting arrow ("red in the shed").
- Pick a landmark in the direction you're travelling and walk to it, then repeat.
- In low visibility (fog, darkness), shorten your aim points and check your bearing more frequently.
Triangulation: Finding Your Position
If you're unsure of your location, triangulate using two or more visible landmarks:
- Identify a recognisable feature on your map and in the landscape (a peak, river bend, ridge).
- Take a bearing to it with your compass.
- Draw that bearing line back from the feature on your map.
- Repeat with a second landmark at a different angle (ideally 60–90 degrees apart).
- Where the two lines intersect is your approximate location.
Practice Before You Need It
Navigation skills degrade without use. Practice in familiar terrain first — local parks, known trails — before relying on these skills in remote or dangerous environments. Consider a formal wilderness navigation course; many mountain rescue organisations and outdoor clubs offer them at low cost. The investment of a single afternoon could one day save your life.