Navigation is one of the most important parts of an expedition. Without good nav skills, your day will be long and could ultimately lead to a failed assessment or worse, result in a dangerous situation.

The Map:

We will always try to provide maps of the area we walk in. We use 1:25 000 scale maps which show the most detail, but sometime you will need two maps to cover an entire expedition.

You may see some 1:50 000 maps around. These are very popular but don't give extra detailed features such as walls and boundaries.

All maps are now in metric form. Each grid square is 1 km apart and contour heights are at 10 metre intervals.

Positions on a map are given by the grid reference. Each square is number and a single grid square is given as follows:

The two digit HORIZONTAL number is given (eg 56) then the two digit VERTICAL number is given. (eg 63) the location grid reference is hence 5663. But this only narrows the point down to 1 square kilometre. In navigation terms this is too vague so we estimate tenths of a grid square. If in our example the point we are referring to is 2 tenths across and 9 tenths up, then the six figure grid reference would be 562639. Always remember, along the hall and up the stairs!

The Compass:

This is very important! Putting it simply, it points you in the right direction (if you know how to use it!).

The Route Card.

This is a list of your journey, divided into 'legs'. Each leg is a section of the route, and has a 'from' and 'to' grid reference. The compass bearing is stated, as well as the distance and any height (net) gain (not loss).

There is space for a short route description and space for working out estimated times.

Before you go

Before an expedition, you must plan your route and write up the card. Once you have settled on a route, divide it into about 8-12 legs. At each point, record its six figure grid reference, making each leg appear on a separate line, as follows:

562639 - 578661

578661 - 605664

etc

Next we need to work out the bearing between the points. This is as the crow flies, not along your intended path. Place the edge of your compass along this line, making sure you point in the correct direction! Now twist the compass housing (the round disk with the numbers on) so that the red lines underneath match the north south grid lines on the map. Now read off the number from the maker point. This number (eg 127) is the number of degrees (out of 360) from north that you are pointing. However magnetic north is about 2 degrees from true north, so in the next column of your route card, you need to record the magnetic north (129) in our example. We need this later.

Now work out the distance. The best way to do this is to use some string or the edge of a piece of paper. Note that this time it is the route we are measuring, not the straight line distance. Record this to the nearest .25 of a km. On a 1:25 000 scale map, 4 cm on the map equals 1 km on the ground. On a 1:50 000, 2 cm equals 1 km.

To work out the height, we count the contour lines on the map that our route crosses in an UPHILL DIRECTION. Each contour line equals 10 metres height. If a route goes up and down, we count all the uphill we climb. For example, if we climb 8 lines (80 metres) then descend 8 lines, our overall change in height is 0 yet we have climbed 80 metres so the height gain is 80m. If we go up 80, down 80, then up 60, down 20 and up 40 all within the same leg, the height gain is 80 + 60 + 40 = 180m. We ignore the downhill. On a map, it is sometimes difficult to tell whether the contour lines are going uphill or downhill. Use other features such as streams (always flow downhill) and roads (most likely to be in the valleys) to help you. As a side note, the closer the contours are together, the steeper your climb!

Use the description space to record a few notes such 'forest on right/west side of path' or 'cross cattle grid at end of track'. It is also useful to record place names.

The time column is split in two, half for leg time and half for on running total time. Leg time is worked out using the following:

1) a set time per km +2) a set time per 10 metres height gained.

In general, with an expedition rucksack, you will walk at about 20 minutes per kilometre. You will ascend at an additional 2 minutes per 10 metres height. To work out your leg time therefore you take the distance (say 3.75km) and your height (180m) and we get a time of (3 x 20 = 60) + (0.75 x 20 = 15) = 1 hr 15 + (18 x 2 = 36) = total of 1 hr 51.

Finally, you should run your finger across your route to that it is in your head. You may want to draw in pencil or use a highlighter on your map as well.

On the hill

This is where your hard work becomes useful! Set your compass to the magnetic bearing we worked out on the route card (131) and line up the red north pointing arrow with the red arrow on the casing. The front of the compass if now pointing to 131 degrees! The time estimates are now useful, as they are good indicators of when the leg is finished, although you should have a logical position such as a junction, bridge or similar to mark the way.

Always know where you are on the map so that if you do go off course, you know where you should be.