Compasses come in a wide variety of styles, but we will focus on the orienteering compass. It's a light-weight, economical compass well-suited for letterboxing, and this tutorial assumes you are using one. This photo shows the major parts of an orienteering compass.
- The needle is what makes the compass a compass. If it's working correctly, the red end should always point to magnetic north.
- The housing is the part of the compass that holds the needle, and it will be liquid-filled and turnable.
- The edge of the housing is called the dial, where the degree markings are located.
- The housing is mounted on a clear, rectangular base plate.
- On the base plate you'll find the direction-of-travel arrow, which is used for pointing your compass and and finding your bearings.
- The index pointer is a line on the base plate (usually the non-arrow end of the direction-of-travel arrow) against which the degree on the housing is read.
- The orienting arrow is marked on the floor of the housing. It rotates with the housing when the dial is turned and is used to orient a compass to a map or to find your bearings.
Your compass might have other features, but these are the basics and the only features most letterboxers will ever need. These types of compasses typically cost between $10 to $20 and can give you decades of use—you'll more likely lose one then have it wear out on you! I use the Brunton Nexus Star compass in this tutorial, but the techniques used here are applicable for any orienteering compass so use whatever you like best!