The magnetic compass has been used for hundreds of years as a navigation tool both by hikers and sailors. It is almost completely infallible and doesn’t rely on batteries or satellites to function. Using a compass to find your direction of travel through the woods or over water is very easy once you learn the basics. When it comes to outdoor skills most people think of building a camp fire or pitching a tent, but one of the most important skills everyone should learn from an early age is how to use a compass.
A magnetic compass works thanks to Earth’s magnetic North and South poles which as the planet spins create a magnetic field that we can use to our navigational advantage. Birds and animals also use the magnetic poles to find their way around during the spring and fall migrations both on land and in the oceans.
The needle on a compass is attracted to both the North and South poles. Whichever pole you are closest to will attract the needle more strongly. The compass needle is magnetized at the factory and works on the magnetic principle that opposites attract. The North half of the needle which is usually painted red in colour is actually the South pole of the needle and the South tip of the compass needle is actually it’s North Pole. Since opposites attract this causes the needle to be attracted to the opposite pole, and therefore always points North when you are in the Northern hemisphere. However knowing which way is North is only a small part of using a compass for following a route.
On most good compasses the needle is surrounded by a rotatable capsule dial which has markings in degrees starting with 0° at the North position, 90° at the East position, 180° at the South position, and 270° at the West position. A good compass also marks all the other degrees from 0° to 359° around the dial. This is very important as the smaller degree markings are necessary to follow a precise path or determining your exact location.
A compass will also have a sighting mark or line or both running through the middle. This sighting mark is used to determine a bearing. A bearing is an angle as measured by the compass. The compass measures angles which are then expressed as a bearing. The sighting mark is on the end of a line which runs down the middle of the compass. This line is called the index and is used to calculate the angles.
To determine your direction of travel, hold the compass flat in your hand at waist height. The sighting mark should be pointing in the exact direction you are traveling. Now turn the capsule until the mark for North is lined up with the red end of the needle. Now look at the index mark, the number on the edge of the capsule that is now sitting on the index line is your angle of travel in degrees also known as your bearing. Let’s say the angle is 237°, if you were to start walking in this direction you would be traveling on a bearing of 237°.
When measuring a bearing, point the sighting mark at a distant yet prominent object such as cell phone tower, mountain peak, tall tree, or any object that stands out. As you travel along your bearing, keep heading directly towards this object. Every few minutes if not more often, check you compass to verify you are still traveling on the correct bearing.
When following a bearing on open water where no landmarks are visible, never take your eye off the compass. It is extremely easy to get off course on open water where no objects are visible to head towards. This method of determining your bearings works only if you are walking or sailing. Bearings taken from a map need to be adjusted for declination, which is the difference between true North and magnetic North before they can be followed by someone on the ground.
The magnetic compass is the most reliable method of traveling in the woods or unknown areas. A compass works in all parts of the world and under all weather conditions including at night, in fog, or a snowstorm. On your next hike in the woods, practice with your family following bearings and teach them how to locate North. Compass reading is an essential skill for everyone who spends time outdoors to learn and best of all, no batteries are required!
Copyright 2016 Mike Wilson