Use of Map and Compass for Hunting
Knowing how to use both map and compass is a fundamental skill for hunters who hunt in unknown country, try new sites, or get away from small patches of cover where familiar landmarks are common. This skill is important to the safety of the hunter. It allows them to find their way out of hunting areas, even if they were temporarily confused, to relocate their camp or vehicle, or to avoid hazards. It is important to the ethical behavior of the hunter, allowing them to identify boundaries between public and private land, to avoid areas where hunting is not permitted, to avoid accidental conflict with neighboring landowners, to relocate downed game for recovery and retrieval. It increases enjoyment by removing the fear of getting lost, planning effective hunting strategies, locating hot spots or sites, or locating water and other needs. In short, it may be as important as knowing how to shoot for hunters who sometimes move off the beaten path.
Understanding and Using a Compass
Many kinds and models of compasses are available to hunters. Nearly everyone knows that the indicator side of the magnetic needle on a compass points to North. North is one of the cardinal points on the compass. These points, North, South, East, and West, divide the compass into four equal quadrants, each having 90 degrees of the 360-degree circle. Even a simple compass can orient the hunter to these cardinal points and give him or her a direction to travel if they know which way to go.
Splitting each of the cardinal directions, that is northeast, southeast, southwest, and northwest, are the ordinal directions. Ideally, a compass used for land navigation should have markings that indicate azimuths or bearings in degrees. There are 360 degrees on a compass, with both 0 and 360 indicating North. East is 90 degrees, South is 180 degrees, and West is at 270 degrees. To find azimuths or bearings, the compass must be held level so the needle can rotate freely, and far enough away from iron or steel objects or other magnets so they do not interfere with the behavior of the needle or dial.
For these exercises, inexpensive orienteering compasses are being used. They have several features that make them valuable to a hunter who relies on map and compass. Each compass is built on a base plate. It holds the rest of the parts together, provides straight edges for aligning the compass with map grid lines or drawing a straight line, includes a direction of travel arrow, and a small magnifier to help with map reading, and has a scale for measuring map distances. The magnetic needle is equipped with an indicator pointing to the North. It rides on a jeweled pivot point inside a compass housing which is often liquid filled to dampen the movement of the needle. The housing or turntable includes orienting lines and degree graduations with cardinal points indicated as well. These features make this type of compass very versatile and useful in the field.
Facing an Azimuth (Bearing)
An azimuth, often used interchangeably with bearing, is a compass direction, an angle of the compass relative to magnetic north. As outlined above, the angle increases around the circle clockwise. Facing an azimuth or bearing means determining the magnetic direction to a selected point, usually marked by some sort of landmark. In order to face a bearing, the person must hold the compass properly; level, away from metal masses, and with the direction of travel arrow pointing away from the body. Rotate the housing or bezel of the compass until the desired azimuth is on the direction of travel arrow. Next, turn the entire body to bring the north end of the magnetic needle in line with the North index or line on the compass housing. Finally, line up the direction of travel arrow with a prominent object as far away as possible and walk towards it. One of the greatest errors made by novices in using a compass is to walk along while looking at the compass and keeping it on the desired azimuth or bearing. This results in a very poor line of travel, since the azimuth is refaced at every step. Locating a landmark and walking to it before locating another one on the selected bearing is far superior and results in a truer line of travel. It is a good idea to have each person take and face the bearing, locate a landmark on the line of travel, and then put the compass away to walk to or toward the landmark. This is not only good compass technique; it is also a confidence builder for the young person.
Shooting an Azimuth
Shooting an azimuth or bearing means finding a direction to another point. Usually some type of landmark is used as the point being determined, as in a point, hilltop, bluff edge, stream mouth, highway intersection, or similar objective. Holding the compass properly, the person should aim the direction of travel arrow at the landmark. Then they should rotate the compass housing or bezel until the north end of the magnetic needle is aligned with the orienting arrow and North indicator on the bezel, while keeping the direction of travel arrow on the desired landmark. The magnetic azimuth can be read directly off the housing where it intersects the direction of travel arrow.
Measuring Distance by Pacing
Plenty of distance measuring tools exist, from measuring tapes, surveyor’s chains, or measuring wheels to laser reflectors. Most of these are inconvenient to use or carry when a hunter is in the field. Fortunately, for every hunter who has two legs can measure distances with something they always have with them – their pace. A pace is the distance covered by two steps. Each person has a normal pace length that fits their height, build, and even temperament. In addition, the pace stays fairly stable in length once the person matures.
Pace length is easily determined. It is best done on flat, level ground in the beginning, with adjustments made for distances taken on uphill, downhill, or broken terrain. Start by laying out a tape at least 100 feet in length. Have each person start with the tips of their toes even with the zero end of the tape and walk normally, counting every time their second foot hits the ground. That is, if they start with their right foot, count every time the left foot hits the ground or vice versa. Have them walk toward an object along the tape without looking at the tape for 15 to 20 paces. Most people and nearly all pre-adolescent kids will be able to get 20 paces inside the 100-foot mark, but some taller kids with long strides may need to stop short of that. Have them repeat this process several times, recording the number of paces walked and the distance where the tip of the toes on the pace foot lines up with the tape. Add all the paces together and all the distances together, then divide the total distance by the total number of paces. That gives you a measure of your normal pace on level ground. A wise person will record that distance so it is not easily forgotten. Once the pace length on level ground is determined, each individual may wish to try measuring distances on the flat, and on uphill, downhill or broken areas where the pace may be altered by the terrain. That will help them to figure correction factors for distance under different conditions.
A triangular compass course can be used to test the pace and orientation skills of participants. One could simply lay out a course that is about 100 feet or longer on its longest side. Provide each participant with a set of four flags or markers that can be planted as they traverse the course. Have them mark the starting point, each turning point, and the endpoint. A 30-60-90 degree triangle makes an easily calculated course with sides in the ratio or 3:4:5, with the long side being the hypotenuse, the short one being the side with the 60 degree angle at its apex, and the middle one being the base, with the 30 degree angle at its starting point. One such course might be to walk a 45-degree azimuth for 60 feet, a 285-degree azimuth for 100 feet, and then 135 degrees for 80 feet. This should lead the young person back to the point where they started. The angles are easily rotated to produce the same courses in other directions, and more advanced young people could be given more complex, even intersecting lines of travel or additional azimuths to determine and walk. Most young people should have some error of closure. This error may be the result of errors in measuring distances, errors in reading the angles, or, more likely, a combination of those errors. In spite of that, the endpoints should be close enough for most hunting conditions. For example, trying to determine the real distance at which a long shot was made uphill, a shooter might want to walk from the animal to the aiming point, then turn and walk back to the animal before using the average distance as the most likely one.
Using Topographic Maps
Topographic maps are rich in information for anyone who knows how to read them. For the hunter who also knows how to read the preferences of game animals, topographic maps are sources of a treasure of information. The border of the map includes several important items. It tells the user the location of the map in the area, the quadrangle name and the scale of the map. Parenthetic information on each edge and at each corner cites bordering quadrangles. Latitude and longitude as well as Universal Transverse Mercator grid points are written on the borders as is the revision date and type, the scale of the map, road classifications, and any unusual marks used on it. Location in the state or province is included, and a declination diagram showing the deviations of magnetic north and grid (UTM) north from map (celestial) north is printed at the bottom. The contour interval is also listed, since this may vary greatly with the site characters and scale.
Contour intervals can be illustrated easily by tracing contour lines onto cardboard or poster board and making a three-dimensional model of them. They reveal elevation and slope as well as topographic features that can be used as landmarks or that offer potential as prime hunting areas. No deer hunter can pass up a high bench or saddle between two steep ridges. No high country turkey hunter can pass up a flat, open area at the head of a south-facing draw or canyon. Marking observations on a topographic map, in code of course, can teach a new hunter where and when to locate certain species or offer some prediction of hot spots in similar country that is unknown.
These maps also include other natural features of interest to the hunter. Bodies of water of all kinds are mapped. Lakes, ponds, and even stock ponds are mapped, as are streams and rivers. On flowing water, contour lines or special markings indicate falls and rapids, and contour lines point upstream, indicating the direction of flow. The nature of streams is also shown, with intermittent streams mapped in broken blue lines. Marshes, swamps, and tidal areas are marked as well, sometimes including depth information.
Some maps include an indication of the vegetation types, using green for forest cover. They also include local names of features, like Old Baldy for a mountain or Skunk Cabbage Creek for a tiny brook. Man-made features, like houses and roads, are indicated, as are political boundaries, like county lines, townships, and the borders of state or federal lands. Cities and towns are indicated with variable detail. Highways and trails of all types are shown on the map as well, with indications of their type and service level. Schools, churches, homes, and outbuildings that were present at the time the smaller scale maps were constructed are shown.
Landmarks can be located from the maps. These should be obvious, relatively permanent structures and stable features that can be used for cues in navigation. Junctions of roads or streams are excellent, as are peaks, sharp turns in valleys, bluffs, heads of canyons, or similar features.
Topographic maps are rich enough in information to permit many hunters to orient themselves and navigate within the area by using the map and landscape features alone. They also point out features that can become reference points as personal experience with an area is built. Problems, like sheer bluffs or deep swamps, can be avoided by reference to the map before setting out to explore the area. Once the area is learned with the aid of the map, it can be learned in person, allowing the person to orient to landmarks and use the area without the need to use additional tools. In spite of that, the ability to use both map and compass together is a valuable skill for outdoorsmen.
Map and Compass
A person with a map and compass and the knowledge to use them is never lost, even if they are temporarily confused. They possess the tools to relocate themselves in the landscape and to plot a course to get them where they wish to be. Combining the structure and features of an area as well as the orientation of the structures and relative locations of features of interest that can be gained from the map with the direction finding ability of compass use frees the hunter from the boundaries of the familiar, the easy and the close-to-the-trail.
Basic land navigation involves learning to put map and compass together to plot locations or calculate courses to destinations. Compass declination becomes important in this process because magnetic azimuths differ from those that can be plotted on the maps for most locations in the world. Most areas will have either an east declination, where the magnetic North is east of map North, or a west declination, where magnetic North is west of map North. This may be of minimal significance in open areas or over short distances; but in dense cover, when long traverses are involved, or where declinations are large, correcting for these errors is critical.
Most hunters are familiar with the term “minute of angle.” They know that a rifle that shoots minute of angle groups will shoot a group of one inch at 100 yards. At 1000 yards, that group would be 10 inches wide ideally. Since there are 60 minutes in a degree, one degree of error would mean that a hunter would be off by 60 inches or five feet at 100 yards, 600 inches or 50 feet at 1000 yards, and 1074 inches or 89.5 feet at a mile. A 10-degree error .is ten times that large, 895 feet or nearly three football fields, per mile. If the hunter were to err by this amount over a ten-mile traverse, he or she could miss their intended mark by over 1-˝ miles. Clearly, corrections need to be made.
Some compasses allow the user to correct the compass to the declination of the map, allowing the user to read map bearings directly from the magnetic scale. Most of us learn to do a little mathematics. Correcting from compass azimuths to map involves adding the compass declination to the azimuth obtained with the compass to WEST declinations, where the compass points to the west of map North, and subtracting the declination from EAST declinations where the compass points to the east of map North. This is used in finding your location from map landmarks or similar situations.
Correcting from map orientation to compass azimuths requires using the opposite action. For maps with a west declination, subtract the declination from the map bearing, obtained with a protractor or compass rose, to get the proper compass azimuth for a travel direction. For east declinations, add the declination to the map bearing to get a compass azimuth. While this may seem a bit confusing, reference to the declination diagram on the map will remind you what to do and which way to go with the corrections.
Triangulation
Triangulation is a technique used to plot a location by determining back bearings from two or more landmarks to the location. The point at which the lines cross on the map is the location from which the azimuths were shot. When using multiple landmarks, the crossing points frequently do not align perfectly. The location is usually within the polygon that is described by their intersections.
That is both a fundamental tool and a very powerful one for the outdoorsman. It enables the hunter to locate him or herself in the area. That allows them to plot a course to reach any desired destination. It can locate a spot to which the hunter wishes to return, perhaps to get into a hot hunting area or to retrieve a big game animal that was too large to bring out alone or shot too late to allow returning to camp with it that night. Knowing the location of the kill or the hot spot on the map and the location of the campo or parking spot, the hunter can plot a compass course and distance to locate the spot again.
The only new skill involved here is the calculation of back bearings. A back bearing is exactly the opposite direction from the azimuth that is shot; it is 180 degrees greater or less than the azimuth. Since North is both 0 and 360 degrees, one may either add or subtract 180 to a South azimuth. IF the azimuth is greater than 180 degrees, it is most convenient to subtract 180 from it to obtain a back bearing. IF it is less than 180 degrees, adding 180 to it is the easiest way to get the back bearing.
For the hunter, knowing this set of skills frees him or her from the need to stick to what is known and close to the road. Knowing the fundamentals of land navigation, the hunter can hunt away from crowds, hunt with security in wild country that is beyond the reach of those who do not have the skills to reach it, to find their way home again with a sense of security, and to have more fun while hunting safely. The more these skills are practiced, the greater their use to the hunter becomes. Eventually, the map pocket in your day bag and the compass on the lanyard attached to your shirt pocket will be as important as your favorite firearm or bow to your hunting success and enjoyment.
