How to use your compass to get around an obstacle blocking your intended route, by Emergency Management Australia

There may be occasions when it will be necessary to alter the direction of travel in order to avoid a major obstacle.

This is best done by traveling around the obstacle by a series of right angles.

To carry out this maneuver with most compasses it necessitates altering the compass setting by 90° each time a change in direction is required.

With the orienteering compass this can be done without any alterations to the original compass setting simply by taking advantage of the right angles of the compass plate as illustrated.

Assume that a user wishes to avoid an obstacle by travelling around it to the right.

• For his first right hand turn he would simply alter the position of the compass in his hand and, maintaining the same setting, sight along the back edge of the compass plate from the left corner to the right corner. The user would then move along the new course for the required number of paces to avoid the obstacle. 
• For the second turn (to the left) the user would hold the compass in the normal way and walk far enough to clear the obstacle. 
• For the third turn (again to the left) the user would maintain the same setting but sight along the back edge of the compass plate from the right corner to the left corner. By travelling the same number of paces as for the first turn it should place the user back on line with the initial direction of travel. 
• For the final turn (to the right) simply orient the compass with the direction arrow pointing directly ahead. 

The obstacle has been by-passed and the user can now continue towards the intended destination. 

Source: This article was adapted from Map Reading and Navigation, Second Edition, (Part IV, Manual 7), by Emergency Management Australia, Attorney-General’s Department; Dickson, Australian Central Territory, Australia. Copyright © 2001. All Rights Reserved. Excerpted with Expressed Written Permission.