Types of compass and their features
Improve your map reading skills with this beginner's guide to the compass. We take a look at the different types of compass, such as a baseplate compass, and explain how to orientate a map with one.
OS Team • Map Reading • May 01, 2022 • 10 mins
Improve your map reading skills with this beginner's guide to the compass. We take a look at the different types of compass, such as a baseplate compass, and explain how to orientate a map with one.
Whether you are out walking or cycling or simply driving somewhere new, being able to use a compass is a great skill that will always come in handy. Rather than just showing north, modern compasses have many features to assist in planning and navigation.
Without a compass, you can still use your map by relying on visible features, but a compass allows you to be more accurate and navigate where there are few obvious landscape features,
There are loads of magnetic compasses available, from ones attached to penknives to huge, expensive ships compasses. Here's some of the most common:
This will tell you which way is north, but without a rotating bezel or an easy way of alignment, it will never be very accurate. They are inexpensive, but very cheap ones can be poor.
Best for: driving and road cycling where you only need the approximate direction, or as an emergency spare
Shop basic compass.
This is probably the most flexible type, as it can be used for taking bearings, setting a heading and measuring distances. The clear base allows it to be laid on top of the map.
Best for: accurate navigation with a map
Shop baseplate compass.
Some more advanced compasses have mirror housing. The mirror allows the user to see the bezel and the landscape at the same time improving accuracy.
Best for: long days in the mountains
Shop mirror compass.
Source: Wikimedia commons - Adamantios
This compass is designed to make it easy to take a bearing from a distant object, and are still often used by the military. They don't have all the features you may want, but can be very accurate.
Best for: people who know how to use them
A compass and its features
How to orientate a map
Where do you want to go?
Adjust for magnetic variationim
Adjust the compass, line up the arrow and follow the direction of travel
Compass readings are also affected by the presence of iron and steel objects, so be sure to look out for – and stay away from – pocket knives, belt buckles, mobiles and GPS devices when using your compass.
The red end of the compass points to north, the black end points to south
As an alternative to using a compass to orientate your map, you can use your eyesight. This method will only work if you are in an area with visible prominent features or landmarks. First, locate yourself next to a feature or landmark and place your finger on the map at the point where you are standing. Then begin to rotate the map so that other features and landmarks on the map begin to line up with the actual ones you can see. The map is now orientated with the land, although not as accurately as it would be using a compass.
Be inspired to do more and go further by equipping yourself with the best tools for the job. Our maps are built on 220 years of experience - we keep walkers, runners, cyclists and more safe in the great outdoors all year round.
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