Navigation training – interpreting the map

To become a competent navigator requires a specific set of skills. In this post we look at navigation training to learn some of the basic skills you will need to find your way when out and about in the hills and mountains – interpreting the map and relating it to the ground (topography).

Understanding the symbols on the map

Maps can have a bewildering array of symbols in various colours, and can initially confuse and alarm those unused to them.

However, help is at hand in the form of the legend, this is the key to the symbols and can be found at the bottom or side of the map sheet. Reassuringly, roads are consistently brown or green, rivers and lakes are blue and woods are invariably green.

A typical map legend

 

Tracks and trails are usually black dashed lines, though National Trails are often red, and individual buildings are small black squares.

It is important to remember those symbols that, as hikers, you will need most; cliffs, scree, paths and marshy ground being some examples. The remainder can be looked up on the legend when you need to identify them.

Understanding contours and relief

Contours are the thin lines drawn on a map, often approximately parallel to each other, in either brown or black. These lines represent points of equal height above sea level, and are labelled at intervals with the height in metres (altitude).

Contours are the standard way of depicting relief, (the shape and height of the landscape), and the patterns a series of contours describe give vital clues as to the relief and the topography of the ground.

Where contours come close together the ground will be very steep, and when well spaced the ground will be much flatter.  When contours form a continuous line, as in a circle, then they describe a top or summit.  Lines drawn at equal height intervals on a hill will appear as concentric circles on a map.

Recognising topographical features

Contour interpretation is a vital part of good navigation but can seem a daunting prospect at first, start by recognising the contour shapes for some of the common topographical features found in the mountain environment; for example, ridges, valleys, hills, saddles and corries.

Once you have learnt to interpret these commonly found features you will soon be able use the finer details to understand the true shape of the landscape from the map, often without ever having been there!

Here are two examples:

A saddle between two hills with spurs at either end
A uniformly steep sided valley

 

In the top illustration the spurs at either end of the hills have shallower gradients than the sides, and make for better ascent/descent routes. The steepest ground is to the north, below the saddle, and should be avoided if the ground if slippery or frozen.

The valley in the bottom illustration is uniformly steep on all sides, as the contours are approximately equidistant, there is no obvious preferable route in this instance.

Orientating (setting) the map

It is good practice to orientate the map before every navigation decision.

To orientate the map using the features you see in the landscape, align the recognisable features, such as hills, cols or rivers, on the map with their counterparts in your field of vision.  The map should be rotated until you have a line of sight from you, through the map feature, and onto the physical feature you see before you.

If you have limited visibility, or cannot locate a recognisable feature in the landscape, you can set the map using your compass.  Line up the edge of your compass with the north/south grid lines on the map.  Holding the compass firmly in place, rotate both compass and map until the magnetic needle also lines up with the north/south grid lines and the red, (north), end of the needle points towards the direction of travel arrow on the compass housing.

Orienting (setting) the map with a compass

The map is now orientated, but it is approximate, as we have made no allowance for magnetic variation.  However, it should suffice for feature recognition purposes

With the map oriented try to locate your position relative to the features you can see in the landscape. Once your approximate position is determined it is then possible to plan your next navigational move on the map, and to give yourself a direction to head in.

Do you see what you expect to see?

Do the topographical features you see on the ground match those on your map? If so, great! If not you need to stop and re-evaluate your position, do not press on blindly hoping that something will fit eventually, because it won’t.

If in doubt you should set the map and try to work out your location, if this doesn’t work and you are uncertain of your position then you should return to the last point where you did know your location, a hill top perhaps.

A good navigator will know where they are at all times, will constantly check their position and confirm their location by using tick features, points recognisable on the map that they might pass, like a stream junction or a forest edge, for example.

Do you see what you expect to see? – Identifying tick features, in this case the end of the Lough.

 

By mastering these techniques you will be on the way to becoming a competent navigator. To progress further you will need to get to grips with using a compass to take bearings, and be able to follow them; and to estimate distance travelled and time taken both on the map and on the ground.

If you wish to learn more about map interpretation and to take the next step, you can join one of our navigation courses held in the Wicklow mountains.

About Author

client-photo-1
neal

Comments

Leave a Reply