Quick Tip: Measuring distance with a lanyard

Suunto A-10 compass with lanyard. From Suunto.
Suunto A-10 compass with lanyard. From Suunto.

A previous article briefly alluded to how I was taught the neat trick of estimating map mileage with a compass lanyard.  What is a lanyard? A lanyard is just a fancy way of saying the string that comes with the compass. 🙂

I learned this little trick through the Narragansett chapter of the  Appalachian Mountain Club during a three-part map and compass class.

What I learned over those sessions still is with me to this day: Looking at contours, reading the terrain, adjusting for declination and other nuts-and-bolts portions of navigation.

And among those lessons was the neat little trick I just mentioned.

So how exactly do you use a lanyard to measure distance on a map?

Simple.

Let’s pretend the red line below is actually the string from a lanyard:

diamondlake

My fingers would be at either end of the red string.  I use a string because it is malleable and can get the nooks and crannies of the trail at least in part.

Now I carefully take that string between my fingers and measure it against the mileage scale found on most maps.

Imaginary red string because I can't take photos of myself that easily. ;)
Imaginary red string because I can’t take photos of myself that easily. 😉

Easy!

In my example above, I measure a little over 2 miles or so one way.

Now, add a 10% fudge factor to make up for the inexact trace…

That trace comes out to just over 5 miles R/T.  Which, no surprise, is also what a popular on-line trail guide states too! 🙂

There are three obvious caveats with this tip:

  • Depending on the amount of bends on the measured trail and your finger dexterity with the string, you may need to take multiple measurements. Simply take note of the individual measurement and then continue.
  • On a similar note, you may need to move the string along the mileage scale to get the total measurements.
  • This tip is absolutely dependent on not letting go of either end of the string with your fingers during each individual measurement.

Don’t have lanyard on your compass? Any thin string will work. Even a shoelace in a pinch.

I do not use this tip as much anymore.  Much easier to trace my intended route out with mapping software. 

In the field this tip is still used on occasion, however.

A stock photo with that darn red string. Convenient! -from Coolspot.gov
A stock photo with that darn red string. Convenient! -from Coolspot.gov

Useful for figuring out an approximate mileage of how far I have to travel to a given point.

And a good tool to keep in the backpacking bag o’ tricks.

 

3 thoughts on “Quick Tip: Measuring distance with a lanyard

  1. maybe adding a small bit of dental floss (tie it to the lanyard) could be an easier way of not having to keep your fingers on the string?

  2. 1:24000 topo maps mostly used for navigation are such a neat thing. 1 mile there roughly equals to the length of my big thumb. So, I don’t need to use no string to be able to predict my mileage. “My thumb says it’ll be about 5 miles”, or “by a rule of a thumb, it’s about 5 miles, mas-o-menos”.

    • Assuming you are always using 1:24000 topos exclusively. A larger, if less detailed map, if better for overall views and is a tool any good navigator should use.

      EDIT: And your thumb may or may not be the same size as me, my wife or a friend. 🙂

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