Map Reading and Navigation

Understanding your map. The basics

There are some basic features that most maps will include:

• Roads tend to be marked in different colours depending on the type

of road depicted. Roads on a map range from thick blue lines, showing
motorways, to dashed lines, indicating an unfenced minor road.

• Footpaths are marked on Ordnance Survey maps in various colours. On a

1:25 000 scale OS Explorer Map the public rights of way are marked in green
and on a 1:50 000 scale OS Landranger Map they are marked in magenta.
There are various types of public rights of way and public access, so please
check the map key for full information. It is important to be aware that
footpaths that are shown in black are not necessarily public rights of way.

• Woods are shown in green with a coniferous or non-coniferous tree shape

printed over the top.
• Buildings are marked by small black squares. However, some particular

buildings have their own special symbols, such as churches and windmills.
Any of these buildings can be useful landmarks, helping you to check your
position on the map.

• Rivers and streams are shown as blue lines. The width of the line is

representative of the watercourse width (if the width of a river is more
than 8 metres it is shown as two blue lines with a light blue area between).
Rivers and streams can be extremely useful in determining your position
on a map.

• Scale tells you how much the land has been scaled down to fit on the

paper. If the scale of a map is 1:50 000 then everything on the map will be
50 000 times smaller than it is in reality.

• Your Ordnance Survey map will also contain other features and information
that will be explained, along with the features above, in the key of the map.

Hiking, of course, is great fun and wonderful exercise, but you can get so much more out of it if you really know where you’re going, and it means you also eliminate the danger of ending up lost on the hills. You can’t always judge your instincts, which is why a good compass, an Ordnance Survey map, and the ability to use them both properly are excellent skills for anyone going out hiking. Of course, you can buy a GPS unit, but remember that batteries don’t last forever, and they also break down – there’s no substitute for some basic map reading and orienteering knowledge.

What Do You Need?
Before heading out you should make sure you have the correct Ordnance Survey map(s) for the area you’ll be covering, and ideally the most up-to-date versions, since features do change.

Additionally, you’ll certainly need a good compass. The orienteering compasses you can buy in camping shops are ideal, with the rectangular base and markings that help you measure accurately on the map. Also carry a watch and a pen or pencil, as well as a torch, so you can read the map at night if you’re caught out.

It’s well worth buying a transparent, waterproof map case that will allow you to easily consult the map and compass in rain and bad weather, which is probably when you’ll need it most.

These tips are nothing more than the very basics. To learn more, there are a number of books or good courses, which are well worth investigating.

The Basic of Map Reading

The OS map really is your friend. It’s a scaled down representation of what’s on the ground, with all the features, either at a 1:25,000 (1” = 250 metres) or 1:50,000 (1” = 500 metres) scale. The map itself is divided into squares, each of which represents one kilometre. The map also shows features, such as churches, which you can recognise from the key, as well as the contours of the ground – the steeper a hill, the closer together the contour rings are.

With those features, it should be easy to relate what you see on the ground to what’s on the map, once you align the map properly so the features you see match the position of those on the paper. From there you can discover your position on the map quite easily by using the squares. Each block of 100 squares is identified by a two-letter code. By using those letters, along with the number of the square, then taking the markings on the orienteering compass to judge your position within a particular square, you’ll be able to pinpoint your grid reference to within 100 metres, which can be vital if you need to call in assistance for any reason.

The Basics of Using a Compass
On a compass, the needle will always point to magnetic North, and that quality lets you use it to find your way in conjunction with a map. If, for instance, you’re on a path that forks, but with no signs, you can use the compass to align the map, and from there see which trail you need to follow.

A compass will also allow you to go on a bearing in your walk, which isn’t as complex as it sounds. It’s simply the angle from north that you want, but you need to bear in mind that what’s shown as North on your map is what’s known as “grid north,” not the magnetic north of the compass. Take your bearing from the grid north on the map, and make your adjustments (the amount will be shown on the OS map). Once you’ve done that, use your compass to establish north on the ground, then follow your bearing. Try it on familiar ground first to become comfortable with it before relying on it to find your way.