An engineer lensatic compass, also known as a hand compass or sighting compass, allows you to take bearings on physical landmarks which can then be used to determine your exact position on a map or navigate toward the landmark even when it can no longer be seen. This type of compass is also commonly used in the military and for orienteering.
1. Lift the front sight of the compass, which also acts as a protective cover, so it is at a 90-degree angle to the base. Position the rear sight so it leans forward over the compass wheel at an angle of around 45 degrees.
2. Raise the compass up to your cheek and look at your chosen landmark through the sights. To improve accuracy, ensure the landmark is in the center of the front sight and fully aligned with the sighting slot above the rear lens.
3. Adjust the position of the rear lens so you can read the bearing on the compass wheel while still maintaining an accurate fix on the landmark.
4. Find your position on a map by taking a bearing on a second landmark then aligning the map so the line on it that indicates north faces the same direction as the magnetic north shown on the compass wheel. Draw lines on the map from the landmarks toward the center using the measured angles. The point where the lines intersect is your current position.
- Photos.com/Photos.com/Getty Images