Knowing how far you’ve traveled is extremely important in back country navigation, and is absolutely vital in applying deduced reckoning, or “dead (actually ‘ded’) reckoning.”
The most fundamental and tried-and-true method – it’s literally ancient – is pace counting. A single pace for the Roman army was two steps of about 30 inches, which created a pace of 60 inches, or five Roman feet. 1,000 of these five-foot paces created the Roman mile of 5,000 feet; very close to today’s statute mile of 5,280 feet. (Even the term “mile” comes from Roman soldiers – mille passum is Latin for “one thousand paces.”)
The metric system and UTM-gridded maps – especially large-scale maps gridded in squares of 1,000 meters (1 kilometer) – might have been made for pace counting and the clever little device that makes it so practical – pace counting beads or “Ranger Beads.”
First, you will need to determine your own average pace count. (And I recommend working in meters and kilometers; it’s a lot easier and converting from meters/kilometers to yards/miles, if necessary, is not difficult.)
First, on a flat meadow, an open park, or a football field, mark out an accurate 100 meters. Next, from your start point, walk your accurate 100 meters at a normal stride, counting your paces. Note that this does not mean counting every step, but every other step; if you start out with your left foot, count every time your right foot comes down on the ground, or vice versa. When you’ve walked your 100 meters, you will have a pace count of something between 50-55 and 70-75. Repeat the process several times, taking care to stride normally, then take the average of your pace count for each time. That, then, becomes your personal pace count.
Let’s say your personal pace count turns out to be 58. That means, then, for every 58 paces you take, you’ll be traveling 100 meters. Simply by counting your paces, you will know how far you’ve traveled.
It follows, though, of course, that counting and keeping track of many hundreds of paces in your head is not practical, and that’s where pace counting beads come in.
The beads shown here are typical; two sets of beads on a doubled cord, with 9 beads on the bottom length and 4 beads on the top, with the knot in between separating the 9-bead set from the 4-bead set.
The 9 beads on the bottom set represent 100 meters each, for a total of 900 meters. Begin with all your beads slid all the way up, then begin walking, counting your paces. When you reach your pace count for 100 meters (in our example, 58), you slide down the bottom-most bead of the 9-bead set, recording that you’ve traveled 100 meters.
Start your pace count over. When you reach your pace count again (here it’s 58), pull down the second bead in the 9-bead set and start over once again.
We see, then, that you’re pulling down one of the 9-bead set for every 100 meters you travel. Once you’ve pulled down your 9th bead (900 meters) and continued ahead for another 100-meter pace count, you pull down the bottom-most top bead, recording that you’ve now covered 1,000 meters (1 kilometer).
With your 1 kilometer recorded, you slide all 9 of the bottom set of beads back up and begin again. In this way you can easily record the distance you’ve covered up to 4.9 kilometers (4,900 meters).
Converting from meters/kilometers to yards/miles is readily accomplished. To convert meters to yards, multiply x 1.1. (100 meters = 110 yards, 300 meters = 330 yards, 500 meters = 550 yards, and so forth.)
To convert kilometers to miles, multiply x .6. (1 kilometer = .6 of a mile, 3 kilometers = 1.8 miles, and 5 kilometers = 3 miles, etc., etc.)
Pace counting beads, often called “Ranger Beads” because of their use by Army Ranger units, can be found for as little as $3.00 to $5.00 on the Internet or can easily be made yourself. (Instructions for doing so can readily be found online; just Google “pace counting beads” or “Ranger Beads.”)