How To Set A Compass

In this example imagine that we are standing at the pumping station (bottom right circle) and want to go to the stream junction (top left).

  1. Line up the base plate– Lay the base plate of the compass between the two points with the direction of travel arrow pointing where you want to go i.e. to the stream junction (See map2).
    note: Using the inner orienting lines of the base plate is more accurate than using the plastic edge of the base plate
  2. Swivel the compass housing until North (red N) points to the top of the map, use the parallel orienting lines on the compass and the blue grid lines on the map to help you.(map3)
    note: you can find the top of the map (grid north) by looking at the writing, most of it runs from west to east with north being at the top.
  3. Read off the bearing, in this instance 312 degree’s
  4. Add 2 degree’s to adjust for the difference between grid north (which the map points to), and magnetic north (which the compass needle point’s to).
    note: this difference varies over time and also with country , this information is usually specified on the map. The variation given here is for Snowdonia in 2007
  5. Follow the bearing– Swivel the whole compass until the red end of the needle line’s up with the North (red N) on the compass housing. Then follow the direction of travel arrow.