Vermilion County Search and Rescue

Basic Land Navigation

How Far Have You Traveled?

Setting Your Own Pace

By Ted Fisher, Vermilion County Search and Rescue

In order to be able to be confident at land navigation you will have to know how to estimate the distance you have traveled along a path. One method used for hundreds of years is called pacing or tally stepping.

PACING:

Basically, this is the practice of calculating distance traveled by counting the number of steps you have walked from Point A to Point B, you then multiply the number of steps by the known distance of your step. A step being the distance you cover from one foot to the other. Another more commonly used distance is the pace. A pace is the distance you covered every time your left foot strikes the ground. (you can also use your right foot just as long as you are consistent.) This pace is sometimes called a Tally Step. I will refer to this distance in this article as a Tally Step. Keep in mind that 2 steps = 1 tally step or pace approximately.

This technique of Pacing or Tally Stepping is a fairly accurate method in determining distances in the field, but you must keep in mind that the distance of your step or pace can vary for reasons such as; terrain, physical condition, and mental condition. Although this method is a good estimate of distance it will not be accurate to the inch, it will get you close however.

Effects of Terrain:

The type of terrain that you are traveling on can affect the distance of your tally step distance whether it is steep or rugged terrain can lengthen or shorten your step. If your terrain is muddy or rocky can also affect this distance. Heavy vegetation and undergrowth deep snow, will shorten your step as well.

Effects of Physical Condition:

What your physical condition is at the time will affect the distance of your tally step. Obviously if you are sick or injured, your steps can be shortened. If you are carrying large loads, such as a heavy pack your steps can be shortened as well.

Effects of Mental Condition:

Similarly to your physical condition, if you’re not at 100 percent mental condition the step distance will be different. If you are fatigued your steps will almost always be shorter.

A combination of one or all of these variables can and will affect your step distance. To correct for this error you must adjust your Tally Step distance accordingly in the type of terrain you are traveling in, and in the present state of mind and body. For instance if you want to know what your tally step distance will be going uphill, then set up known distance course uphill, walk it and determine your tally step. Do the same for other terrains.

Determining Your Tally Step Distance:

Determining your Tally Step is very easy. Measure out a straight-line course on the ground of a known distance such as 100 meters or 200 feet, place a marker such as a flag or stick at the starting point and one at the ending point. Start with your right foot walk this distance 3 or 4 times keeping track of how many times your left foot strikes the ground between the two points. Average the number of steps and divide the distance between the start and finish points by the average number of paces. This is your tally step. For example: 200feet/40 paces = a 5 foot Tally Step. These courses can be setup in different terrains to see the effect on distances. It is also good to know your tally step in metric measure as well, because UTM grids are in the metric system and thus eliminates the need for conversion.

Tally Step or Pace

Step

Keeping Track of the Distance Traveled:

Many people that use pacing in land navigation find that some way to keep track of tally steps is beneficial, so if they get distracted at some point in their travel they can easily refer to it to jog their memory of the distance. Beads on a string, pebbles in your pocket, knots in a cord, or a written record are just a few of the ways that are used to enhance your memory.

Relating Field Pacing to Map Distances:

Land navigators should be aware of the error factor in map distances to actual travel distances on the ground. Maps measure distances from two points in a straight line or “as the crow flies” for the most part. Unless the terrain that you are in is totally flat this distance will vary from actual walked distance because no correction has been made for uphill or downhill distances. So in hilly terrain a walking distance calculated from a map of 5 miles could actually wind up being 6 miles when you walk it.

Examples of Use:

Example A.

You have set up a course to determine your Tally Step of 200 feet. You have paced off the course 4 times listed as follows:

1. 41 paces

2. 40 paces

3. 41 paces

4. 40 paces

Which averages out to be 162/4 = 40.5 paces drop the .5 pace for 40 paces.

Take your course distance of 200 feet divided by 40 paces which = 5 foot tally step.

Example B.

You have determined from your map that you need to travel ½ mile to your next point. How many tally steps for ½ mile? ½ mile = 2640 feet, (take 2640) divided by (tally step of 5 feet) = 528 tally steps.

Example C.

You have traveled 256 tally steps on an azimuth of 260 degrees and need to know what your current position is. 256 tally steps times 5 foot tally step = 1280 feet.

Other Methods Used:

Other methods of calculating distances that you should be aware of are Terrain Association, Time Traveled, Electronic Range Finders and Ped-O-Meters. These topics will not be covered here in detail, but brief descriptions are included.

Terrain Association requires that you have a map in hand and periodic calculations of distances as you go. You relate the features you see in the field to the map and then calculate distance traveled.

Time Traveled method involves how long you have been traveling and at what speed. I find this method somewhat less accurate than pacing, but it is a good guideline as a backup to pacing. You need an accurate time piece and you need to know how fast you travel. This method is also affected by the above mentioned factors.

Electronic Range Finding requires you to purchase the range finder, which is somewhat more bulky than a pair of binoculars. The unit measures distances by a laser or by optics. These usually will require a good reflective target for the laser, and a direct line of site to the target as well. The optical range finder requires you to setup a known distance prior to measurement.

Ped-O-meters have also been used although I have not tested these in the field, and do not know how reliable they are for varied terrain.

Conclusion:

With Pacing or Tally steps a fairly easy and accurate determination of distance traveled can be obtained. By using a combination of techniques a double check can be obtained to verify each technique; a sort of backup. Therefore the ultimate goal of successful Land Navigation can be maintained. To those new or inexperienced in Land Navigation, do not get frustrated by trying to get accuracy down to the inch. As this would be difficult because of the variables and factors that affect these techniques.

Practice, Practice, Practice… this system and your accuracy will improve if you do, you will be amazed at just how close you will be with this simple low cost technique.