Before the cloud arrives

Mist on a ridge is rarely a surprise. It usually announces itself as a grey smudge creeping up the corrie, or a dampness in the air that dulls the tops an hour before the cloud finally swallows them. That window is your best chance to prepare, and it costs you two minutes.

Stop, put on a layer, and take the map out of its case properly. Find your exact position while you can still see something — a cairn, a stream junction, the point where the path bends around a spur. Mark it mentally against a grid line, not just "somewhere near the summit". Then work out your next two legs on paper: the bearing, the distance, and the feature you expect to meet at the end of each one.

Check the map's marginal information too. The contour interval is printed in the legend, and it differs between sheets, so never assume. The same panel gives magnetic variation for the year — in Britain it is small, usually under three degrees, but if you are walking a long leg in poor visibility it is worth knowing rather than guessing.

Orienting the map and reading the ground

An oriented map is one whose features line up with the landscape. Place the compass on the map, align the edge of the baseplate with any north–south grid line, and turn yourself and the map together until the red needle sits inside the orienting arrow. Now the map is a small model of the ground around you.

In mist this single habit prevents most errors. With the map oriented, you can compare shapes rather than guess at them. Contours become the language you read:

• Tight, closely spaced contours mean steep ground — crags, gully sides, the flanks of a corrie.
• Widely spaced contours mean gentle slopes and easier walking, often where old paths run.
• V-shaped contour bends pointing uphill mark a stream or re-entrant; pointing downhill they mark a spur or ridge.
• Closed rings are summits or hollows, depending on whether there is a spot height or a depression symbol inside.

Practise this in clear weather until you can glance at a slope and predict what the map will show. That skill is what carries you when you can see nothing at all.

Taking a bearing that actually works

Lay the compass on the map with its edge running from your position to your target. Make sure the direction-of-travel arrow points the way you intend to walk. Rotate the bezel until the orienting lines sit parallel with the grid lines and the orienting arrow points to the top of the map. Read the number at the index line.

Then correct for magnetic variation: add it if it is west, subtract it if it is east. In Britain this is a small adjustment, but "small" is not the same as "ignore".

Now the bit most people skip. Hold the compass flat at waist height, in front of you, and turn your whole body until the red needle settles inside the orienting arrow. The direction-of-travel arrow now points along your line of travel. Look up, pick out a feature in that direction — a boulder, a patch of scree, a particularly sullen tussock — and walk to it. Do not stare at the compass while you walk. Use it to check, then walk to a real object.

Measuring distance with pace and time

A bearing without distance is only half a leg. There are two reliable tools, and using both together keeps you honest.

Pacing. Count double paces — every time your left foot lands. On level ground most adults take around 60 to 70 double paces per 100 metres, but that is a personal figure. Measure it on a known stretch of path, then measure it again on rough ground and uphill, because the number changes.

Timing. A common planning rule is roughly 5 kilometres per hour on easy ground, plus about one minute for every 10 metres of ascent. It will not be exact, but it gives you a second opinion when your pacing feels off.

Handrails, aiming off and catching features

Three techniques turn a wobbly bearing into a reliable plan.

• Handrails are linear features you can follow instead of steering by needle — a boundary wall, a burn, a fence line, a broad ridge. If a wall runs near your route, walk the wall and save your concentration.
• Aiming off means deliberately steering a few degrees to one side of your target so you know which way to turn when you meet the feature. Aim off to the left of a stream junction, for instance, then follow the stream up until it forks.
• Catching features are the things beyond your target that tell you if you have overshot — a lochan, a path, a sudden steepening of the ground. Identify one before you set off, and note what you would do if you meet it.

When you lose confidence

Stop. Not in a minute, not at the top of the rise — now. Walking on while uncertain is how short errors become long ones. Get out of the wind, eat something, drink something, and put the map away for a moment to let your head settle.

Then relocate systematically. Find a definite feature you can identify: a stream, a wall corner, a contour shape that matches only one place on the map. Work outward from there rather than trying to guess your position from nothing. If the cloud is thick and the day is short, turning back down a known bearing is a good decision, not a failure.

The walkers who navigate well in mist are simply the ones who practised the basics on clear days until they became boring. Boring is exactly what you want when the ridge disappears.