You need to learn some navigation skills to complete expeditions independently and safely.
This means being able to use a map and compass and to follow your route accurately.
There are 5 basic navigation skills to learn.
They are quite easy and important to attempt to master.
- Setting the map (orientation)
- Grid references & map symbols
- Using contours
- Using compass bearings to find the right path
- Estimating time and distance
How much do you know already? Take this quiz!
The maps you use for DofE are 1:25,000 scale
On 1:25,000 maps 4cm = 1km (100,000cm).
The 1:25,000 scale means that any distance unit on the map (for example the width of your finger)= 25,000 times that distance on the actual ground.
So 1cm on the map would become 250 metres in the real world i.e. 1cm = 25,000cm.
SKILL 1: Setting the map “Where are we?”
Setting the map means turning it to face north / south.
An oriented map means it matches the scenery around you so it faces the direction of travel. This is usually enough to tell you where you are. Set the map in two ways:
- Use landmarks to match up the map with the surroundings:
In good visibility you can set the map by eye. Find roads, paths, walls or streams. Spot these features on the map and line them up with the ground. Turn the map so that the features on the ground line up with the map.
2. Use a compass to point the map exactly North – South:
If identifiable features are not visible you can set the map using the compass. Use the magnetic needle to find north and line this up with the grid lines on the map. It is now orientated or “set”.
With your map now oriented, features should be the same direction on the map as they appear to you on the ground.
This action is vital for accurate navigation! Do it frequently! This video shows you two ways to set your map.
SKILL 2: Grid references and symbols: “We are exactly here!”
All OS maps have a key printed on them, like the one below. These have the relevant symbols for roads, paths, water and land features, etc.
Symbols are essential for navigation because they give you a precise location. Keep track of what symbols and features you expect to see coming up on your route. Keep your thumb on your location and move it along to pin down where you are.
Grid references
OS maps have a series of numbered horizontal and vertical ‘grid’ lines, which allow you to pinpoint any location with a unique reference number. These ‘grid references’ are used to tell people exactly where you are, or where you’re headed – vital to help people find you in an emergency and for planning hikes.
How to do grid references
Remember … “along the corridor and then up the stairs”
You get a 4 figure grid reference for a 1km square from the numbers of the grid lines that bound it to the west and south.
The vertical lines are given first and are called “eastings” because they’re numbered eastwards, they are followed by the horizontal lines or “northings”.
To give a 6 figure reference look along the bottom or top edges first and find the number of the square, then estimate the site’s exact position in tenths of a square. Then you do the same along the left or right edges. The numbers are also printed every so often on the map, which makes things easier.
SKILL 3: Contours: “Is it up or down?”
Recognising map symbols like roads, railways, buildings and masts is easy but sometimes there are no obvious symbols around. To navigate properly you need to be able to interpret the shape of the land (relief) on the map by using contours.
When planning routes it is important to “keep height”. This means once you have climbed a hill, you don’t want to lose the height immediately. Avoid unnecessary ups and downs; these will quickly tire you out.
Learn to spot the following contour features:
- Steep concave slopes: contours closer together uphill
- Shallow convex slopes: contours further apart uphill
- Flat slopes: constant distance apart uphill
- Hills and valleys
- Re-entrants (small valleys)
With practice, you’ll be able to imagine the shape of the land from contours.
SKILL 4: Compass bearings: “Which way do we go now?”
A compass is just a metal needle that points to magnetic north.
The needle has a red end (“Red Fred”) which points to magnetic north.
Red Fred sits in a “housing”, marked with graduations running from 0 to 360 degrees. Across the base of the housing, there are a series of parallel ‘orienting lines’ and an arrow. These must be aligned with grid north on the map when taking a bearing.
Other features include various scales to measure distances on the map and a ‘direction of travel arrow’ that tells you which direction to walk.
A compass is mostly used to set a course from where you are to where you want to be.
Compass rules:
- Hold it flat and steady; let the compass needle settle down.
- Avoid metal / magnetic objects (e.g. NO ipods, phones nearby etc).
- Take care of it … it might really save your life one day!
Taking a simple bearing from a map: deciding which path to go on!
To take a bearing between two points follow these steps:
- Locate where you are, point A, and the point you wish to walk to, point B.
2. Align the compass edge so that it forms a line between these two points. Note that the compass should be facing in the correct direction.
3. Hold the compass firmly on the map. Rotate the bezel so that the faint vertical lines (orienting lines) align themselves with the vertical (blue) grid lines on the map.
4. You can now pick up the compass. Turn your compass (and you) until the red needle is positioned over the North arrow on the compass housing. We call this “Putting Red Fred in his shed!”
5. Now walk in the same direction as the Direction of Travel arrow.
If you wish to walk in a straight line from A to B, keep an eye on the compass and follow the direction of travel arrow. You must take care to ensure that the two red pointers (north-south and red marker on the bottom of the dial) remain aligned (i.e. keep Red Fred in his Shed!).
Walking on a bearing in a straight line is not easy in mountainous terrain, especially in bad weather (when you are most likely to need a compass). Slopes, streams, bogs, cliffs and rocks can all push you off course despite following your bearing (i.e. you can “side slip” without knowing).
To maintain a straight course on a bearing (“dead reckoning”) study the technique illustrated below. The technique is Gold standard but important to understand now.
A note on magnetic variation:
Magnetic North (where your red compass needle points) lies to the west of True North (the North Pole), which itself lies to the west of Grid North (north/south grid lines on UK maps). The position of Magnetic North changes slightly each year, moving east by approximately 0.5 degrees every four years. In Britain in 2007, Magnetic North was about 3 degrees west of Grid North and this is decreasing.
This magnetic variation means that you should adjust your compass before you can follow a bearing on the ground with spot on accuracy.
When transferring a bearing from the map to the real world, you must rotate the housing to the west (anti-clockwise), adding on the current magnetic variation of 3 degrees in the process.
- “Map to Ground = add”;
- “Ground to Map = subtract”
*notes:
- A 2 or 3 degree magnetic variation is so small that it hardly makes any difference to the accuracy of your bearing over short distances. So you can ignore it so long as you keep bearings short!
- Remember that magnetic variation varies throughout the world and it’s always stated on the map. In some places you will need to account for a large magnetic variation.
When to use a compass
The secret of not getting lost is to get your compass out while you still know where you are. This way you can use the compass to take you through the cloud or to check a path to your desired location.
Use a compass:
- To check which path to take
- To check the exact direction across trackless mountains
- To keep on route through bad weather
SKILL 5: Estimating time and distance
“How far is it?”
You must be able to measure distances accurately between places on a map. The Royal Marines video below tells you several ways to measure distances on maps. These are essential to use when planning routes but also measuring distances in the field.
Maps are produced in the UK so that every grid square is 1km by 1km.
On the expedition, getting a distance estimate from OS maps is easy since the grid lines on all OS maps are 1km apart – simply count the number of grid squares between the points and this give a rough idea of the distance in kilometers.
You can measure distances more accurately using the compass romer scale. When planning your route you can use the edge of a piece of paper or a piece of string to measure distances accurately or Memory Map will give you accurate distances for each leg.
“How long will it take?”
For hikes with a full rucksack:
Allow 3 kilometers per hour plus 10 minutes for every 100 metres climbed (1 minute per contour)
This means that walking 100m on the flat will take your group two minutes.
You can calculate how long it should take to walk a certain distance if you know your average walking speed. The table below will help you!
NB: Most groups with expedition rucksacks walk comfortably at a pace of 3km/h.
Your actual walking speed “on the ground” will vary from around 3kph to 5kph.
- 3 kph means you will cover 1km in 20 minutes or 100m in 2mins
- 4 kph means you will cover 1km in 15 minutes or 100m in 1.5mins
- It is not usual or recommended for groups to walk faster than 5kph.
Your walking speed will depend on fitness, terrain, load and weather.
Once you have established your group’s average walking speed you can use this to help you navigate very accurately.
Keep an eye on the time and distance traveled throughout your hike and contact your assessor if you are going to be late to a checkpoint.
Being consistently late to check points may mean you fail your hike.
“How far is it?”
Pace counting is another important navigation skill. Watch this video to find out how to pace count..
Counting your paces as you walk can tell you how far you have gone.
To pace successfully you need to know how many double paces you take for every 100 metres. Double pacing is better than single as it reduces the level of counting.
Work out your own pace count by walking normally over a known distance, ideally repeating it a few times to get an average.
Remember slopes or poor conditions underfoot will require an adjustment and steep slopes will shorten your stride dramatically.
Only count double paces: count each time your right foot hits the ground. Pace counts are used to estimate short distances: especially in bad weather or in the dark in difficult terrain.
Reigate Grammar School DofE 