Devil Dogs

a. Plotting an Azimuth. To plot an azimuth from a point on a map, the sniper will:

I) Place the protractor’s index at that point.

2) Rotate the protractor until the base line (N-S. 0 degrees to 180 degrees) is parallel to the nearest north-south grid line.

3) Make a tick mark on the map at the point indicated on the protractor’s degree scale for the desired azimuth.

4) Remove the protractor and draw a line from the starting point to the tick mark. This line represents a grid azimuth.

5) It is essential that the protractor index lines be precisely parallel with the grid lines. A slight variation from the parallel will result in a measurement error of several degrees.

6) Verify measurement by extending the drawn line between the two points until it intersects with a grid line, place the protractor index exactly on the point of intersection of the N-S grid lines and read the azimuth.

b. Plotting Back Azimuths. During land navigation, the sniper may find himself having to backtrack. This is done by determining a back azimuth. The back azimuth is the reverse direction of the original azimuth. It is like doing an about face or making a 180 degree turn. To obtain a back azimuth from an azimuth the sniper merely has to:

1) Add 180 degrees if the azimuth is 180 degrees or less.

2) Subtract 180 degrees if the azimuth is more than 180 degrees.

3) An easy way to remember this is to use the acronym LAMS - less add, more subtract.