Compass & Pacing

Description

Compass and pacing requires a competitor to locate a specific point that is between 1980 and 3300 feet (30 to 50 chains) from their starting point using nothing more than a compass. There must be at least four different segments on the course. The compass is used to determine direction, while pacing is used to determine distance. Either bearings (e.g. S45W) or azimuth (e.g. 225 degrees) may be provided, while distances can be in feet, chains, or yards. Hand calculators are permitted. Competitors must know their pace beforehand, which can be accomplished by walking a known distance while counting steps. Of course this becomes more complicated when the course passes through dense shrubs (brush chaps are allowed), moves up or down hills, or crosses streams. Experienced competitors know how to adjust the count of their pace to account for such obstacles. The winning contestant is the person with the highest relative precision ratio, which is calculated as the length of their course divided by the distance they were from the true end point. Once a course is begun, the competitor may not return to the starting point and is only awarded a precision ratio if they complete the entire course. Compass and pacing has been a Conclave event every year since at least 1960.

Compass & Pacing Example Photos

Photo Credit: Student using a compass to take an azimuth at the 58th Southern Forestry Conclave hosted by Mississippi State University. Thanks to the Mississippi State University Forestry Club for providing the photo.

Photo Credit: Student pacing to estimate distance at the 58th Southern Forestry Conclave hosted by Mississippi State University. Thanks to the Mississippi State University Forestry Club for providing the photo.

Academic Background

Compass and pacing is an essential skill for foresters navigating off-road areas by foot. Even with modern GPS technology, some forested areas receive poor satellite signals and equipment can always break, become lost, or lose power. This basic ability to navigate is essential for timber cruising, wildlife habitat assessment, wetland delineation, or any other activity that requires working in the woods. Compasses come in a variety of styles, and can be procured from Amazon, Forestry Suppliers, or dozens of other vendors. Compasses function based on magnetism, and thus they point towards magnetic north. Magnetic north is not the same as geographic north (i.e. the north pole) due to complexities in the earth's magnetic fields. Thus compasses must be declinated to adjust for the difference between magnetic and geographic north. Even though declination is relatively small across the US South, it can still cause major errors when compass and pacing long distances, such as those prescribed for this Conclave event.

Photo Credit: Magnetic versus geographic north on a compass, commonly called magnetic declination. CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1976224

Photo Credit: Magnetic declination changes depending on where in the world you are. It also gradually changes over time, as depicted in this GIF showing it drifting from 1590 to 1990. U.S. Geological Survey (USGS) Public Domain, https://commons.wikimedia.org/w/index.php?curid=1733830

Resources

Compass & Pacing Course Generator

This spreadsheet can be used to generate practice courses. Be certain to check the course you create with aerial imagery of your practice site first for safety issues and problem areas such as roads, fence-lines, structures, water bodies, and private property or other restricted areas. This will only be accurate on perfectly level ground as it is based solely on trigonometry, but error may be minimal on gently sloping sites. It also does not account for magnetic declination. Simply input the distance in chains for each of up to 10 legs to a course, and the azimuth in degrees. The bearings may be entered by hand (see below for a conversion guide). The cumulative deflection from start to end provides you with the distance and direction that you should be from your starting point after completing the course. For the graphical map to work, download the XLSX file.

Comparison of Azimuth and Bearing

Photo Credit: A comparison of azimuth and bearing notation. http://academic.brooklyn.cuny.edu/geology/leveson/core/linksa/comp.html

Compass & Pacing by ForestryWorks

Click HERE to view the video on YouTube.

Forestry Management Skills - Compass & Pacing

Click HERE to view the video on YouTube.

Silva Navigation School

Click HERE to view the video on YouTube.

How to Adjust for Magnetic Declination

Click HERE to view the video on YouTube.

Declination Adjustment - Brunton Compasses

Click HERE to view the video on YouTube.

Compass & Pacing Extension Pub

This document is a combination of extension publications from the University of Kentucky and North Carolina State University. If the document does not load below, click to download the PDF.

Event Layout Example

Thanks to Dr. Scott Roberts of Mississippi State University for providing this example layout map from the well-administered 58th Southern Forestry Conclave compass and pacing event in 2015 hosted by MSU. Five different yet equivalent traverses were laid out, so that three flights of five competitors could complete the event in a timely manner. If the document does not load below, click to download the PDF.