Guest Author - Lisa Linnell-Olsen
Using a map and compass is a basic and important outdoor skill. GPS units may have great features, but when a GPS fails it is time to go old school and get out the map and compass. Use your map and compass to get comfortable with them before you go on your next trip.
1) Parts of a Compass- There are three parts you need to be familiar with. There is the base or protractor, which is the flat part you lay on your map. The dial is the rotating feature found in the middle, often marked with degrees. The needle is the moving part that points north/south. On most compasses the side of the needle that points north is red.
2) Orient the map – Place your map on a flat surface, such as a rock or a backpack, laying flat. Place the compass on top of the map. Turn the map so that it is facing the direction that the compass needle indicates.
3) Adjust for declination – magnetic north and true north are different. Declination is the difference between the two. Your map should have an adjustment printed on it in a lower corner to guide you in making the correction. Turn your compass the correcting number of degrees to adjust for declination.
4) Locate a landmark – Find a landmark a few miles off, one that you can see on your map and from your location. With your compass still on the map, point the compass arrow on the protractor at the landmark. Rotate the dial so that the needle points north. While maintaining the needle direction and the degrees on the dial, move the compass so that you can use the protractor to lightly pencil a line at the landmark on your map.
5) Repeat step 4 for a second landmark feature. Lightly extend both lines until they cross. The cross over point is your location on the map.
6) Now that you have found your location on your map, you should be able to use your map to continue on your course for your trip. You can repeat this process at any time to find your location on your map.
Tip: Avoid using your compass near any other magnetic objects. Some cameras and knives are magnetic.
Practice and experience are important. Make sure you practice using your map and compass before you go into the backcountry.
Landscapes change over time. Make sure you get the most up to date map available that meets your needs, and find out if there are any changes to the landscape that have occurred since it was printed.