I prepared these notes for the Social Evening in June. They may be of more general interest around the club. I’m afraid however that you missed making an exhibition of yourselves in running up and down my road over a 100 metre stretch.
- What is it?
A simple technique to tell you roughly how far you have gone from a chosen start point. It is invaluable if you are going for a bingo pit in an otherwise featureless forest. But mainly you will use it to support your map reading e.g. “This is too early for the stream that I’m looking for so it must be an unmapped ditch.”
- When to use it?
Some say almost never! Others say whenever possible! So try it and decide for yourself. I use it unconsciously all the time & have to think hard to stop myself doing it. Start off by trying it on level paths to confirm, say, a junction or where you expect a veg boundary to hit the path. Then try it on up/down hill paths. Finally try it on cross country legs. Remember the further you go and the rougher the terrain the more unreliable is pace counting. At first don’t attempt to pace count for more than about 100 double paces on flat paths or 50 double paces in nice clean forest. The big danger of pace counting is that you are tempted to switch off from reading the map. You will have to keep practising pace counting until it becomes just a minor background activity in your mind to your main task of following the map.
On your map measure how far you want to go. Convert this into double paces for running or walking Run or walk and count off a double pace each time your right (or left) foot hits the ground. Try not to rely on pacing alone, get any other information you can from the map. If, on your way, you see and recognise a feature on the map then re-measure from it and re-start your pace counting.
- Measuring how far to go.
Most compasses have an edge with a marked centimetre scale. Use this to measure how far to go E.g. 1½ cm You may chose to scratch a scale on the underneath surface of your compass so that you can quickly measure distances on the map without moving the compass. I have done this for years.
- Convert to double paces.
You need to carry in your head (or stuck on your compass) how many double paces you need to cover 1cm on the map. Let’s say this is 60. (You find this out by calibrating yourself, see below) In your head multiply the distance (1½ cm) by 60 to give 90 double paces. Now move forward 90 double paces.
- Your calibration.
You only need one calibration to start with ie how many double paces to run (or to walk, if you normally walk) 100 metres, which is 1 cm on 1:10000 map. This is best done at first in a special training exercise with 100 meters marked out on a straight path. Make sure you calibrate yourself using the gait that you naturally fall into in an event. A 10minute run may be advisable before calibrating yourself to establish this. When your pace count over several tries has settled down to about the same on each 100m leg, make a note of this number. Now change it to the nearest 10 or 5, to make it a bit easier to do the mental arithmetic during an event.
For example, change a calibration of 67 to 70 or 54 to 55. If your calibration is now, say, 70, then write down:
1:10000 70 1:15000 100 (i.e. 70 + ½ of 70 = 105 & rounded down to 100 for ease of use)
The number of double paces to take is given by: Distance to go (cm on the map) X calibration factor (paces per cm for this map scale) Take this sheet with you to each event & memorise your calibration for the map scale of this event just before you go to the start.
Your pace counting will vary with terrain & with tiredness. As a rough guide try the following corrections. Experience will help you to refine them for yourself.
Walking: Increase the paces required by half (if you calibrated yourself running)
Uphill: Increase paces by half.
Downhill: Reduce paces by half
Across Country: Increase paces by half
When tired: Increase paces by half.
Pace counting is a personal thing. It needs a lot of practice at first and even then you may decide to not use it. I get the impression that those who are instinctively good navigators use pace counting the least. So, as most of us are mediocre navigators, it should be useful for the majority.
Some thumb compasses have the main scale divided up at 2/3 of 1cm. This is fine. Do the calibration as above for the two map scales and then take 2/3 of them both and write them down. Now measure the distance to go in terms of the divisions on your compass and apply the calibration corresponding to the map scale.
There is a different approach to calibration, which some people prefer. They calibrate themselves over 100 metres as above. They then measure the distance to go on the map in meters. They do this either by using the metre scale shown on every map or by having a metre scale on their compass for both 1:10000 and 1:15000 maps. They now have to remember only one calibration number for all maps ie paces per 100 metres. Their double paces are given by:
Distance to go (as 100’s of metres on the ground) X calibration factor (in paces per 100 meters).