Monday, March 05, 2018

No map? Charting a Course with only a Compass


CHARTING A COURSE


USING A COMPASS ALONE





 [Nyerges has been teaching outdoor survival skills and preparedness since 1974. He is the author of “How to Survive Anywhere,” “Guide to Wild Foods,” and other books. He can be reached at www.SchoolofSelf-Reliance.com, or Box 41834, Eagle Rock, CA 90041.]



Let’s say it’s dark, or overcast, or you’re traveling in thick woods.  You don’t have a map, but you have a compass. You’re not traveling in a straight line, but going here, going there, finding out what’s out there.



There’s a way that you can take records of your travel, and then chart a direct path back to your camp or car.  It’s not that difficult, but it does require a compass, and a pen and notebook.



Let’s say you’ve driven to a remote area in the forest and you want to explore a large area for possible camp sites. You set out at 27 degrees, and you walk for 20 minutes.  You make two columns in your notebook, and you record 27 in the degrees column, and you record 20 in the time column.



Then, you decide to change directions, and you head out at 150 degrees. You write that down in the “degrees” column.  You walk for 30 minutes before you pause, so you record 30 in the minutes column.



You continue this way for the rest of the day, always recording the degree in which you walked, and the amount of time you walked in that direction.



Now, before we get too far along, let’s review (for you beginners) how to determine what degree you are walking. With  your orienteering compass, you point the “direction of travel” arrow – which is the printed arrow on the housing of the compass -- in the direction you are traveling.  So far so good?  Now, you turn the round dial until the printed arrow is directly over the north end of the needle.  OK?  That’s pretty basic compass use.  Sometimes we refer to that step as putting the dog in the house.  The printed arrow looks sorta like a dog house, and the magnetic needle (the “dog”) must be kept aligned with the “doghouse.”  As long as you keep the dog in the house, and follow your “direction of travel” arrow, you’re accurately traveling at whatever degree you’ve decided to walk in. 



Obviously, for this system to work well, you need to walk in fairly straight lines.  In fairly rugged terrain, this system might not be practical or possible.



So, let’s say you’re done exploring for the day, and your notebook contains 6 entries for degree traveled, and 6 entries for amount of time traveled.



With that information, you are now going to create a simple map to determine a straight path back to your camp or wherever you started from.



Let’s take a look at the notes  you took, in the example, and how to turn those notes into a map.



Here is an example of what your notes might look like.



DEGREE
OF TRAVEL
TIME TRAVELLED
27
20
150
30
240
20
180
20
285
30



Remember, this is just an example, and in the example, we have kept the units of time all divisible by 10 minutes.  In real life, your units of time would likely be much more diverse.



Using your notebook, or using sticks on the ground, you will turn the units of time into linear lengths. So, for example, each ten minutes of time traveled will be one inch.  It doesn’t really matter whether you make each ten minute segment represent one inch or five inches or the length of your finger or the length of your Swiss army knife – just be consistent with whatever unit of conversion you use. 



So let’s say you are going to use sticks to create a map. For your first 20 minute leg of your journey, you cut a straight stick 2 inches long (10 minutes = one inches).  Lay the stick on the ground and align it at 27 degrees, your direction of travel.



Your next leg of your journey was 30 minutes, at 150 degrees.  So you cut a stick that is

three inches long.  From the leading end of the first stick, set down your three inch long stick and align it at 150 degrees.  So far so good?  You are creating a map of your journey.



Next, you cut a two inch stick and align it at the end of the last stick at 240 degrees.

Next, cut another two inch stick and align it at 180 degrees from the end of the last stick.

Finally, you cut a stick three inches (30 minutes = 3 inches) and set it at the end of the last stick at 285 degrees.



OK? You have just created a visual map of  your journey using stick, converting time into linear lengths.  When you have completed your stick-map, you now place your compass at the end of the last stick (which represents where you stopped, and decided you wanted to go home), and point it to your starting point.  That is your direct line back to your camp.  Put the dog in the house on your compass, and simply follow the direction of travel arrow back home. 



And because you have chosen each 10 minutes of travel time to represent one inch, you can just measure your straight line back to your camp to get a good idea of how long it will take you to get home.



From my reckoning, it appears that you can now walk straight at 30 degrees, for about 35 minutes and you’ll be back in your camp!  Not bad, considering that your entire journey so far took two hours.



Now, we did not discuss the variables that come with uneven terrain.  That is, if you had a lot of uphill travel, you probably couldn’t cover as much terrain in 10 minutes as you could if the ground were flat.  So you should record these terrain changes in your notebook.  If you walked for 20 minutes, that would normally represent a two inch stick.  But if the terrain was very sharply uphill, you wouldn’t have been able to cover the same distance in the same time.  You would estimate, and probably use just a one inch stick for that leg of your journey.  You should also record any changes in the speed of your hiking, though this works best if your speed is more or less the same.



There’s a bit more to this, so please come to one of my Orienteering workshops when you can. 
See the Schedule at www.SchoolofSelf-Reliance.com.

Also, get a copy of each of these following books:

The Green Beret’s Compass Course,” by Don Paul, 2006.  The technique described in this article was based on  his book, available from Amazon.

Be Expert with Map and Compass” by Björn Kjellström is still one of the best overall guides to map and compass use. Available at Amazon.

 How to Survive Anywhere” by Christopher Nyerges includes a short section on navigation.

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