Why the “triangulation technique” to get unlost is a bad idea

Many navigation books and classes teach a slick-sounding technique known as triangulation to locate your position on a map if you are lost.  In theory, it works like this.  From your position (unknown) you take a compass bearing on two or more visible landmarks.  If you then plot these bearings onto your map, the intersection of the lines is your approximate position.

This sounds great in a warm classroom or cozy reading chair, but for triangulation to work, you need three variables to ALL line up in your favor.  Here are those three, and some examples why this technique often fails in practice. 

1. Triangulation requires that you be able to actually see two or more features on which to shoot a bearing.  If you’re lost in heavy tree cover, at night or in low visibility, you’re out of luck.
2. Triangulation requires that you be able to match the feature you see in the field to your map.  You’re lost, but it’s daylight and you’re able to see several nearby peaks.  Trouble is, you are not sure of their names.  Being able to see and take a bearing to a peak, lake or other feature is useless unless you can positively identify the feature on your map.
3. Triangulation requires that the feature you see in the field actually be on your printed map.  You’re lost in the Columbia River Gorge, and from a high point you catch a distant view of Beacon Rock.  Too bad that Beacon Rock is not on your printed map, making that feature useless for triangulation.

You can see that the triangulation technique has a host of flaws.  There may be rare times when it works, but don’t rely on it alone to get you unlost.

(To close on a slight positive note, sometimes just getting a single bearing to a feature and plotting it on your map can be a big help.  At least you know you are somewhere on that plotted line.)