Navigation: How to Use a Compass

Part of a compass

When paddling, you use a compass to determine or identify courses, bearings and headings. Because the deck of a kayak or the workstation in a canoe is small, limiting the number of instruments used for navigation speeds up the process and reduces the chance of losing an item overboard. A baseplate compass combines a protractor with a bearing compass, and it fits inside a lifevest. Learning how to use one simplifies the process of navigation.

Parts of a Compass

Part of a compassIndex line: Read the bearing in degrees at this line. In the images, the index line read 43 degrees.

Direction of travel arrow: This points towards the bearing. Use the arrow and the center of the magnetic needle like a site when holding the compass out in front of you.

Compass dial: The compass dial rotates. It shows the cardinal directions and the degrees.

Orienting arrow: When the red end of the magnetic needle aligns with the orienting arrow, the index line shows magnetic degrees from north.

North-south lines: Used to align the compass to a map.

Housing: A fluid filled enclosure of the magnetic needle.

Magnetic needle: Piece of metal, painted red and white, that points towards magnetic north.

Transfer a Course To a Bearing

When you know where you are on a map and want to know which direction to travel to a destination, you use the compass as a protractor to find direction to the destination, and then transfer the direction to a distant object near it using the compass as a bearing compass. It takes just three steps.

  1. Align the long edge of the compass with your starting point and your destination on the map. Make sure the direction of travel arrow points towards your destination.
  2. Turn the compass dial until the north-south lines are parallel to the north-south lines on the map. The orienting arrow should align with north on the map.
  3. Hold the compass straight out in front of you. Turn the canoe or kayak until the orienting arrow and the red end on the magnetic needle align. The red end will point to the north symbol on the compass dial. The direction of travel arrow now points at the destination. Pick a feature along the shore and paddle towards it.

After Step 2, the index line indicates the course in true degrees. If your kayak or canoe is equipped with a built-in compass, turn the boat until the compass reads the same degrees as shown on the index line.

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If true north and magnetic north differs in the area you’re paddling, you need to adjust for variation. Also, check for deviation.

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Transfer a Bearing to the Map

If you want to relate a feature in the distance to the map, you take a bearing to the feature and then transfer that to the map. It takes three steps.

  1. Hold the compass straight out in front of you and point the direction of travel arrow at the feature. Turn the compass dial until the orienting arrow, north on the compass dial and the red end of the magnetic needle align.
  2. Set the compass down on the map with the bottom of a long edge touching your position.
  3. Rotate the entire compass around your current position until both the compass’ and map’s north-south lines align. The long edge now points towards the distance feature.

If you don’t know where you are, but you do know where the feature is on the map, you can align the top end of the compass’ long edge with the feature on the map in Step 2. This gives you a Line of Position. You are somewhere along that line. You can combine two Line of Positions to find a Fix.

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