Getting your team from A to B amid the complexity of military manoeuvres can be tricky enough. But when the mist rolls in, things can quickly grind to a halt.
In such situations, a good grasp of navigational basics will get you out of trouble, says Cpl Tom Somerville (RE), a technician at the Defence Geographic Centre and a trainee mountain guide.
These are his tips for staying on track.
1. Stay calm and maintain situational awareness
Retaining a relatively confident fix on your position is key. You can then apply the following methods to ensure the accuracy of your next movement.
2. Orientate Use your compass to keep track of north, east, south and west at all times.
Ensure the top of the map faces north by aligning the needle with the eastings the vertical gridlines. The red end of the needle should point towards the top.
3. Use dead reckoning
This technique, perfected by the Long Range Desert Group to help them navigate the featureless terrain of North Africa in the Second World War, focuses on a series of set bearings and distances from a known start point.
It's useful when visibility is reduced, too, but robust measurement of pacing and timing plus accuracy of bearing is essential.
4. Spot natural features
If cloud cover suddenly clears, this is your chance to take bearings off anything you can confidently identify on the map or ground.
Plot the back bearings from as many visible features as possible and work out where they intersect to improve your position fix.
5. Use a partner as a marker Where vis is poor or the terrain lacks features, send a member of your team out on your intended bearing to the limit of visibility.
Get them to stop there until the rest of the group moves to that location, then repeat the procedure. It's essential your marker sticks as close to the bearing as possible - if they veer off course, correct them.
As long as you stay on track, maintain a fix on your position and ensure your bearings and distances are accurate, this will keep things moving in the right direction.
