We all know how to use our phones to navigate, but they couldn’t be more useless in an emergency. The second you lose your signal or the battery dies you lose your maps and even your compass. Even when they’re functioning they’re not very accurate in the middle of nowhere. So every man needs to know how to find their way using the equipment and techniques that explorers and sailors have been using for centuries.
Maps & Charts
A map is a visual representation of an area looking down from above. I know you probably already knew that but the best instruction articles assume no knowledge on the part of the reader. Most maps on phones are road maps, which as the name implies focus on the layout of the roads and streets. Road maps are only useful when you’re on or near the roads, so they’re pretty useless in the wilderness. What you probably want is either a topographical map or nautical chart. The former focuses on elevation of land and the latter shows depth below the water. A good map is always well labeled so you shouldn’t have any trouble finding landmarks, which can be crucial later on. Maps also include information unique to that map, such as compass declination (more on that later on) and scale. Also, you always want to buy your maps as soon as you can before you need them, so you aren’t trying to use an outdated map with landmarks that don’t even exist anymore.
A compass has two main components; a needle and a graduated dial, one of which is magnetized. There are lots of different kinds of compasses, but you’ll want a map compass and a lensatic compass. The map compass, as the name implies, is used in conjunction with a map to find bearings to places you can’t currently see. The lensatic compass is used to takes bearings to places you can see. Any compass can be used quite effectively to find your heading, so don’t waste money and space in your pack on a third compass, it’ll never help you. Compasses do have one fatal flaw; they can be disrupted by ferrous metals, other magnets, and electronic and electrical equipment. For that reason you should also know some other ways to find directions.
The Map Compass
A map compass has a few distinctive features. First is the card, it has several essential markings printed on it, most notably the rulers around the edges. There’s also a magnifying lens to help you read your map and holes that can help you make markings on your map. The most important though is the rotating compass housing. Rotating this is how you calibrate the compass, but more on that later.
The Lensatic Compass
A lensatic compass can be most easily be distinguished by its case. There is a rectangular opening in the lid with a wire running lengthwise through it, a rotating bezel with two lines on it (one of which runs through the centre of a magnifying lens, and folding viewfinder with a second magnifying lens.
Finding Bearings from a Landmark
First you need to find a landmark, it can either be one you can find on your map or one that you know where it is relative your destination. Next you open your lensatic compass. The lid should be opened to a ninety degree angle and the viewfinder to forty-five degrees. Turn the bezel so the line that doesn’t pass through the magnifying lens lines up with the wire. Now, hold the compass at eye level and against your cheek so the notch in the viewfinder frames the bottom end of the wire. Turn to face the landmark so it’s right behind the wire. Look through the viewfinder’s lens and once the dial stabilizes the line will point to your bearing.
Find Your Position Using a Compass
This part is pretty cool. You can actually find your precise location using nothing but a map, compass, and some basic drawing tools. First you take bearings to two landmarks on your map. Then, draw straight lines on your map going the opposite direction from the landmarks. You’re where the lines intersect. It’s best to only do this when you’re stopped, because it gets less accurate the faster you’re moving. You compensate somewhat by simply taking less time to take both bearings.
Finding Bearings on a Map
One of the most important parts of navigating with a map and compass is finding your bearing to your destination. After all, you can’t get there if you don’t know which way to go.
First you’ll need to find your position on the map. You can either use the technique above, find your location marked on the map, or use any other technique you may have at your disposal. Finally, position your map compass along an imaginary line running through your current location and your destination, with the arrow pointing in the necessary direction of travel. Next, turn the compass housing so it aligns with the orientation of the map. Now adjust for declination, this should be printed somewhere on the map and refers to the difference between the directions of magnetic and true north. The arrow now indicates the direction you need to travel to reach your destination. If you keep the compass housing from turning on the card you can find your way by keeping the needle pointed towards the north mark on the compass and the arrow facing forward, just make sure you find your bearing frequently to keep on track.
Finding Your Heading
If you feel the need to figure out which direction you’re headed you can use any compass. If you’re using a map compass you’ll need to start by lining up north on the compass with the direction of travel arrow. Next just hold the compass in your hand. Whatever direction the needle is pointing at is your heading.
There you have it. You now know the basics of navigating using a map and compass. In the future I’ll be writing articles on more advanced map and compass skills, including how to use a sextant.