Fog and poor visibility

When fog, low cloud or heavy snow closes in, familiar ground can suddenly look unrecognisable. Careful navigation and a willingness to slow down keep you on track.

Before visibility drops

If you can see fog or cloud coming:

1. Work out exactly where you are on the map.
2. Take a compass bearing to your next point.
3. Note what features you'll pass on the way.
4. Drop a waypoint in the app so you can find your way back.

Should you keep going?

Ask yourself whether you can navigate safely. If the ground ahead includes cliffs, steep drops or open water, or you are unsure where you are, it may be better to stop, shelter and wait for it to lift. Fog often clears later in the day, but it can also last for days on high ground.

Navigating in fog

• Walk on a bearing. Use your compass and check it often. Without landmarks, people tend to drift in curves.
• Leapfrog. Send one person ahead to the edge of visibility, in line with the bearing. Walk to them and repeat.
• Use handrails. Follow a path, wall, fence or stream that leads where you want to go.
• Count your paces. Know how far it should be to the next feature.
• Aim off. If you're heading for a point on a long feature, like a bridge on a river, aim deliberately to one side. When you reach the river, you'll know which way to turn.
• Use catching features. Pick something you can't miss beyond your target, like a road or stream. If you reach it, you've gone too far.

Staying together

• Keep the group close, within sight of each other at all times.
• Stop and regroup at junctions and regularly in between.
• Agree a signal if someone gets separated: a whistle, with replies.

Hazards in poor visibility

• Cornices and cliff edges can be invisible in fog or white-out. Stay well back from edges you know are nearby.
• Sounds travel differently in fog and can seem to come from the wrong direction.
• Drivers can't see you. Wear bright or reflective clothing near roads and walk facing oncoming traffic.
• Fog is damp and chilling. Put on warm and waterproof layers early.

If you lose your way

Stop. Don't wander hoping to recognise something. Go back to your last known point if you can, or follow the steps in the guide on what to do if you are lost. Waiting in a sheltered spot is often safer than moving blind.

White-out

In snow and fog together, the ground and sky can merge into a featureless white. Throwing a snowball ahead of you can help show where the ground is and whether it drops away.

This article is in the Grid Survivor app, searchable with no signal. Get the app · £4.99