# Using a compass

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## How to use a compass with Simon King and Ordnance Survey

### Introduction

This guide will help you to understand how to use a compass. This is a vital skill for walkers and hikers to help them navigate and stay safe. Ordnance Survey (OS) maps are essential for any walk in the UK.

### What you'll need

*   A compass
*   An Ordnance Survey map of the area you are walking in
*   A flat surface to lay your map and compass on

### Setting up your compass

1.  **Hold your compass flat.** It is important that the compass is perfectly level for accurate readings.
2.  **Align your map.** Orient your map so that it is facing the same direction as the terrain you are walking in. You can do this by matching features on the map to features you see around you.
3.  **Place your compass on the map.** Place the compass on the map so that the long edge of the baseplate is aligned with a north-south grid line. Make sure the direction of travel arrow is pointing towards where you want to go.
4.  **Rotate the map and compass together.** Keeping the compass perfectly level, rotate the map and compass together until the orienting lines inside the compass housing are parallel to the north-south grid lines on the map.
5.  **Read the bearing.** The bearing is the number on the dial of the compass that lines up with the direction of travel arrow. This is the direction you need to walk in.

### Taking a bearing from the map

1.  **Place your compass on the map.** Position the compass on the map so that the edge of the baseplate connects your current position to your destination. Ensure the direction of travel arrow is pointing from your current position to your destination.
2.  **Rotate the housing.** Keeping the baseplate still, rotate the compass housing until the orienting lines inside the housing are parallel with the north-south grid lines on the map. Make sure the orienting arrow inside the housing is pointing towards north on the map.
3.  **Read the bearing.** Lift the compass carefully away from the map. The bearing is the number on the dial that lines up with the index line (usually marked with an 'N' or an arrow). This is the direction you need to walk in.

### Following a bearing in the field

1.  **Hold your compass level.** Hold the compass flat in front of you at waist height.
2.  **Turn your body.** Turn your body until the 'N' on the compass housing lines up with the magnetic needle. The direction of travel arrow will now be pointing in the direction you need to walk.
3.  **Pick a landmark.** Look up and find a landmark (like a distinct tree or rock) in the direction the arrow is pointing.
4.  **Walk to the landmark.** Put your compass away and walk towards the landmark.
5.  **Repeat.** Once you reach the landmark, take your compass out again and repeat the process, picking a new landmark in the direction of your bearing. Continue this process until you reach your destination.

### Using the compass to find north

1.  **Hold your compass flat.** Ensure the compass is level.
2.  **Let the needle settle.** Allow the magnetic needle to settle. The red end of the needle usually points to magnetic north.
3.  **Rotate the housing.** Rotate the compass housing until the orienting arrow lines up with the red end of the magnetic needle.
4.  **Read the bearing.** The 'N' on the compass housing now indicates magnetic north.

### Important tips

*   **Practice makes perfect.** The more you practice using your compass, the more confident and accurate you will become.
*   **Be aware of magnetic interference.** Metal objects, power lines, and certain types of rocks can interfere with your compass reading. Be mindful of these potential sources of error.
*   **Always carry a map and compass.** Even if you are using a GPS device, it is essential to have a map and compass as a backup.
*   **Learn to recognise the symbols on your OS map.** Familiarise yourself with the various symbols and features on an Ordnance Survey map to enhance your navigation skills.

This guide provides a basic understanding of how to use a compass. For more detailed information, consider attending a navigation course or consulting additional resources from Ordnance Survey.

Migrated from [https://www.mkramblers.org.uk/Know_Your_Compass.htm](https://www.mkramblers.org.uk/Know_Your_Compass.htm) on 2026-09-19 10:08