Two tools, one job

Ask most hillwalkers whether they carry a GPS and you will usually get a slightly defensive answer. Some treat it as a backup they hope never to need. Others rely on it entirely and quietly worry that they shouldn't. The truth is more relaxed than either camp suggests. A GPS device and a paper map with a compass are not rivals; they are two halves of the same job, and using them together makes you a calmer, more accurate navigator than either tool could manage alone.

The principle is simple. Your map and compass tell you what the ground should look like. Your GPS tells you where you actually are, to within a few metres on a good day. When those two agree, you can walk on with real confidence. When they disagree, something has gone wrong — a misplaced grid reference, a misread bearing, a compass near a magnetic buckle — and it is far better to notice that in the middle of a pleasant afternoon than in the middle of a cloud base at dusk.

What a GPS does brilliantly

There is no shame in admitting that a handheld unit or a phone app is superb at certain tasks. It will give you a grid reference in seconds, which is invaluable when you need to confirm you are on the right spur before committing to a descent. It will tell you how far you have come and how far remains, which matters on long days across open moorland where everything looks encouragingly similar.

• Confirming a position when you are unsure but not lost — the classic "am I on this contour or the one below?" moment.
• Recording a track so you can retrace your steps in mist or darkness without guessing.
• Checking distance and ascent against your timing estimates.
• Finding a specific point, such as a tent pitch, a bothy or a path junction, in poor visibility.
• Logging your route afterwards, which is a genuinely useful way to learn how your pacing and your map reading compare.

Used this way, a GPS is a confirmation tool. It sharpens your navigation rather than replacing it.

What a GPS cannot do

Here is where the defensive walkers are right. A GPS has no idea what the terrain between you and your destination looks like. It will happily draw a straight line across a river, over a crag edge or through a bog that has swallowed better boots than yours. Only the map shows you the shape of the land — the steepening contours, the crag symbols, the marsh hatching — and only you can judge whether that line is walkable.

It also cannot tell you the direction of travel without a signal, cannot warn you that the weather is turning faster than your plan allows, and cannot be relied upon to keep working. Cold drains batteries. Water gets into seals. Screens crack against rock. A device carried in a hip belt takes knocks all day long. And satellites are not always obliging — deep in a wooded valley or beneath a steep crag, your unit may take several minutes to find a fix, if it finds one at all.

You, on the other hand, need no batteries. A map and compass work in the dark, in the rain, after a fall, and after a week in a rucksack.

The cross-check habit

Make a routine of pairing the two. Before you set off, take a grid reference from the map and mark it on your route card, then check it against the device once you are moving. At every significant feature — a stream junction, a wall corner, a path fork — glance at the map, take a bearing if needed, and then confirm the position on the screen. If the numbers match your reading, note it and walk on. If they do not, stop. Eat something. Work out which one is lying.

The most valuable check of all is the deliberate one: pick a moment mid-morning, mid-afternoon and at every decision point in poor visibility. Confirm where you are, work out where you are going, and rehearse the bearing before you move. It takes under a minute and it turns a GPS from a crutch into a second opinion.

When the screen goes dark

Assume it will. Carry the map in a waterproof case, folded to the relevant section and accessible without stopping to unpack your whole rucksack. Keep the compass on a lanyard around your neck rather than buried in a pocket. Keep the GPS somewhere warm — an inside chest pocket is far better than a lid pocket in a hard frost — and carry a small power bank, itself kept warm, if you are relying on a phone.

Know your own fallbacks too. If the device dies, you should be able to pace out a distance on a bearing, time a leg against your estimated speed, and follow a handrail feature such as a wall, stream or ridgeline until it meets something you can identify with certainty. That is not an emergency skill. It is ordinary navigation, and it is what keeps a long day on the hills enjoyable rather than memorable for the wrong reasons.

Practise on familiar ground

The place to build these habits is a route you already know well — a local hill, a stretch of coast path, a forest trail you have walked a dozen times. Take a bearing you do not need, then check it on the device. Estimate your arrival time, then see how close you were. Deliberately cover the screen for half an hour and navigate purely by map, then uncover it and see how you did.

Do that a handful of times and the two tools stop feeling like alternatives. They become one method, and you will walk with the quiet assurance of someone who always knows where they are — and can prove it.