Hiking navigation basics: map, compass and phone

How to read a topographic map

A topographic map shows the shape of the land with contour lines. Each line joins points at the same height.

• Close-together contours mean steep ground; widely spaced contours mean gentle slopes.
• V shapes pointing uphill are usually valleys and streams; V shapes pointing downhill are spurs and ridges.
• Scale: 1:25,000 means 1 cm on the map is 250 m on the ground. 1:50,000 means 1 cm is 500 m.
• The contour interval (often 10 m or 20 m) is printed in the legend. Count lines to estimate how much you'll climb.

Before the walk, trace the route and note handrails (paths, streams, walls or ridges you can follow), catching features (something that tells you you've gone too far) and the points where you'll need to make a decision. This fits into the wider day hike plan.

How to take a compass bearing

A baseplate compass lets you walk a straight line in poor visibility. To take a bearing from the map:

1. Place the edge of the compass along the line from where you are to where you want to go, with the direction-of-travel arrow pointing towards your destination.
2. Turn the dial until the orienting lines in the housing line up with the map's north-south grid lines, with the orienting arrow pointing to map north.
3. Adjust for magnetic variation if needed. It differs by place and changes slowly over the years; the current value and direction are usually printed on the map or available from national mapping agencies.
4. Hold the compass flat in front of you and turn your body until the red end of the needle sits inside the orienting arrow. Walk in the direction of the travel arrow.

Pick a landmark on that line, walk to it and repeat. Practise on an easy day so it isn't new when you need it.

Using phone GPS and offline maps

A phone's GPS works without mobile signal, but the map tiles don't. Download offline maps of the whole area, not just your route, before you leave home.

• Load the route as a GPX track and check it against the paper map.
• Learn how to read your coordinates or grid reference from the app so you can give your location in an emergency.
• A track on a screen doesn't show cliffs or swollen streams. Use the contours and your eyes as well.

How to make your phone battery last

• Start with a full charge and carry a power bank and cable.
• Use airplane mode with location still on when you only need GPS. Searching for a weak signal drains the battery fast.
• Turn the screen brightness down and close apps you don't need.
• Keep the phone warm in an inside pocket in cold weather. Cold batteries can shut down at what looks like a healthy charge.
• Keep it in a waterproof bag or case when it rains.

What to do if you're unsure where you are

1. Stop. Don't keep walking in hope.
2. Think back to the last place you were certain of, and how long ago that was.
3. Look at the land around you and match it to the map: valleys, ridges, streams, slopes.
4. Check the phone's position against the map.
5. If you're still unsure, retrace your steps to the last known point, or follow a safe handrail towards a known feature.

Paper maps don't run out of battery. Keep one in a waterproof bag and know which way is north before you need it.

Poor visibility is one of the reasons to turn back covered in weather and mountain safety. Map, compass and a charged phone are all on the hiking packing list.

Hiking navigation FAQ