Ten Essentials Overview: Map and Compass
Written by Hester Lam, Girls Who Hike Texas Ambassador
When going to the backcountry, it is a good idea to always be prepared for the worst. When going on day trips, I always have items from REI’s Ten Essential Systems. If lost, having the Ten Essentials might be the difference between making it out of the hike relatively unscathed or much, much worse.
The first item in the ten essentials is navigation. In particular, navigation stresses the necessity of learning the basics of using a compass. A compass is most useful if there’s no clear geographic feature (e.g. looking straight at the Dawn Wall in Yosemite) to orient yourself. To most successfully use a compass to get yourself un-lost, it is best to have a topography map of the area. If you’re able to look at your surrounding area and have at least 2 tall features around you (generally mountains/ hills or rivers/ lakes), you can get a pretty good idea of where you are.
Components of a compass:
A free-floating needle (with red typically being North)
A transparent plate with a direction- of- travel arrow which points in the arrow toy are moving towards
A rotating housing (dial) marked with the four cardinal directions and 360° tick marks
An orienting arrow at the bottom of the housing
An index line on the base plate. The point where this line meets the tick marks is where you take your reading.
Tips for Using the Compass
0° is north. 90° is east, 180° is south, and 270° is west.
Make sure that your red needle is actually pointing north and not at something extremely metallic (e.g. someone’s belt or trekking poles)
Make sure your compass is level, and at least arm’s length when reading the bearing (you are magnetic, so you don’t want to skew your readings!)
Taking the Bearing
Align your needle with the index line
Holding the compass in front of you, turn your body and the compass together until the needle is aligned with the orienting area. The direction- of- travel will be pointing north.
Pick a landmark. Any landmark! A tree, a mountain, etc can all be great landmarks! Turn your body and compass until the direction- of – travel arrow is pointing at your landmark.
Keeping your arrow pointed at the landmark, rotate the housing until the orienting arrow is aligned with the needle.
Read the bearing in degrees for the landmark off the index line
Triangulation on a Map
Now what? How do you get from knowing where your bearings are to getting yourself out of your lost situation?
First, choose two to three topographic features that you can see and can identify on your map (great examples include mountain tops, lookout towers, bridges, lakes, and distant campgrounds).
Start with the first feature and take a bearing between you and it as you’ve learned above
Once you have determined this bearing, pencil in the line with the map that runs through this feature
Repeat with your other features, drawing lines for each
The point where the lines intersect is where you are!
REI offers a basic map and compass class that ranges in price from $30-$40 dollars if you’re a member or $40-$50 if you’re not. Youtube also has some great videos here and here. However, the best way to learn how to use a map and compass is to practice. Get topography maps of local areas, find a place that you are familiar with such as a campground or mountain top (and can use to “check” your work), and keep taking your bearings until you’re used to it!