This is an On-line version of what we have taught in class and field settings.

The purpose of this training is to continue to familiarize the SAR team member with using maps and compasses, how we deal with declination, and how to use triangulation to figure out where you are. As team members we all recognize that a GPS is a handy tool, but ignoring the basics is not wise. These skills are perishable.

Orient The Map

As a part of every map & compass class, the first thing we teach is to orient any topo map being used in the exercise to the terrain, then adjust as necessary the map to the compass using magnetic bearings (ignoring true north lines).

We then extend magnetic north lines from the topo map's magnetic line across the face of the topo map. These new "reference north" lines are now the only north lines needed.

The beauty with this method is as follows:

1) No adding or subtracting declination
2) All bearings taken by team members are magnetic
3) Simple compasses without declination settings are preferred

Take Bearings to Notable Landmarks

From your fictitious location, somewhere in the middle of the map, you should be able to point out at least three notable land formations. This exercise assumes you are in a class, not the outdoors, but can be extended to an outdoor exercise easily. Mark the three locations on your map, and add more "reference north" lines mentioned earlier to intersect your location, and jot down the bearing you took from your location towards each of the three.

In this example I marked the direction of travel and noted them on the map. However it pays to note the back azimuth while your taking a bearing.

Plot Directional Lines

Using a compass you will need to plot three reference lines relative to the known spot on the map and the known bearing. Easier said than done. This can be quite confusing in a class setting, but think about the problem this way. If you had a full compass rose like the one shown below, you could draw a line that passes through the center of the rose then straight through the bearing, making sure it passes over the top of your landmark. Note that the rose is positioned with North zero degrees along the "reference North" line.

Of course not everyone carries a compass rose in the field. So here's a more field-friendly approach using a standard compass.

(1) Orient the map by putting it on the ground and using your compass, ensure the reference North lines are precisely pointing North.

(2) Dial into your compass the bearing.

(3) Put your compass on the map and rotate the entire compass (not the outer ring) so that the needle lines up parallel with the orienting lines. Your direction of travel (side of compass) should now fall along the line of your bearing and back bearing.

(4) Carefully line up one edge to intersect your landmark without rotating the compass.

(5) Draw your line.

Repeat for the second and third landmarks.

You Are Here

Assuming there is always a degree of accuracy (or inaccuracy) you should see a triangle where the three lines intersect. Your location should be within that triangle. Always use three bearings at a minimum. Using only two gives you a single point reference, and unless your measurements are flawless, will probably not be exactly where you are. Note on this example any 2 of the 3 lines gives you a different intersecting point. Which is right?