Using a Compass – The Basics

Using a Compass

I quite often run into fellow backpackers during my hikes and enjoy chatting with them about where they’re from and what they’re doing, the usual trail chit-chat.  A lot of the time our conversations include discussions about the current hike and conditions along the trail, where to find water and areas to avoid if necessary, sharing information with fellow hikers is one of the best parts of meeting people along the trail, in my opinion.

However, on more than one recent occasion (too often, in fact) the conversation has included the seemingly innocent question of “so, where are we on the trail – any idea?”  To which I am always shocked and usually ask, “don’t you carry a map and a compass?”  This elicits several knee-jerk responses, the most frequent being, “yes, but I’m not exactly sure how to use the compass,” along with a sheepish grin.  Inside my head I’m thinking, “then why are you carrying it and how on earth do you navigate your position?”

Using a map and a compass is such a fundamental part of being outdoors or hiking that it should be one of the very first things that you learn before setting off to the wilderness.  For heavens sake people, learn the basics, it just might save your life one day.  So to that end, I thought I’d explain the basics of how to navigate with a compass using a map and how to determine your current position using a compass and your bearings.

Anatomy of a Compass

First, let’s start with understanding the parts of the compass, knowing what they do, and how to use them.  Then we’ll use a simple three-step technique to apply this knowledge to navigating direction using a map. Below is a photograph of my hiking compass. It’s by no means one of the more expensive models available, but it is a quality device that I know will work when I need it to. My particular compass model is a Silva Polaris and costs about $14. It’s easy to use, accurate, reliable, and compact.

Anatomy of a Compass

  1. A small length of centimeter increments along the left side of the base plate for measuring
  2. The plastic base plate helps keep the compass level and flat
  3. The direction of travel arrow is used to navigate towards your desired destination (see below). It is also used as the Index Line for taking a bearing reading
  4. These lines help to orient the correct direction for north from your map
  5. The orienting arrow is used to make sure that the magnetic needle is always pointing north, thereby giving you the correct direction of travel
  6. Most good quality compasses have liquid filled capsules that house the magnetic needle. It helps the needle settle down more quickly
  7. A small length of inch increments along the top edge of the base plate for measuring
  8. USGS map scale ruler (1:24000) used for measuring distances on your map
  9. Rotating dial with degree graduations. Used to determine your bearing
  10. The magnetic needle always points in a north/south direction.  The black or sometimes red end of the needle indicates magnetic north
  11. Declination is a way to make very small adjustments to your bearing to account for the difference between magnetic north and true north
  12. My compass didn’t come with a cord attached, but it did have a lanyard hole.  About the best thing you can possibly do is to add a small length of sturdy cord to your compass.  I use blaze orange tether cord because it’s strong and will help me spot my compass if I drop it on the ground

How to Use a Compass

Step 1: Lay your map down somewhere flat if you can and place your compass on top.  Draw a line between your starting point and your destination to show the direction of travel.  Now, line up the base plate edge with the direction in which you want to go, represented in the photo by the highlighted line on the map.

Using a Compass - Step 1

Step 2: Keeping the base plate edge of your compass in line with your direction of travel, carefully rotate the graduated dial until the N, orientation arrow (5), and orientation lines (4) are all pointing in the direction of north on your map. On most maps north is straight up, but make sure you check with the legend on the map that you are using, I’ve seen maps that do not adhere to this cartographic convention.  Ignore declination for now, if accuracy is not critical and the distance you have to travel is not enormous, you should be able to use the compass without declination adjustment.

Using a Compass - Step 2

Step 3: Remove the compass from the map and hold it level out in front of you with the direction of travel arrow (3) is pointing straight ahead. Turn your body until the north end of the magnetic needle (in my case it’s the black end, sometimes it’s red) is directly over the orienting arrow (5), pointing to the “N” on the dial.

The direction of travel arrow is now pointing in precisely the direction you want to travel in order to reach your destination. The easiest way to use your compass now is by using the “snap a line” method.  While holding your compass in the direction of travel, look up and sight a landmark or object that is not too far away and is in the direction you want to travel.  Put your compass away or hang it around your neck and start walking towards the landmark or object that you spotted. Once you reach it, repeat the process by holding your compass as before making sure it is still set according to your map, sighting another landmark, and walking to it.  Continue doing this until you reach your destination.

Using a Compass - Step 3

How to Find Your Exact Position on a Map

Now that you know how to use a compass to navigate in the direction you want to travel, the next step is to learn how to determine exactly where you are along that path at any give point. This is another important use of a compass and another important lesson worth learning.

In order to determine your position, you will need to choose two visible landmarks that you can easily identify on your map. Power lines, bends in rivers or streams, mountains, and lakes are perfect for this.  Choose two that you can see from where you are standing and mark them on your map as L1 and L2.

Holding the compass directly in front of you, point the direction of travel arrow toward the first landmark (L1) and rotate the compass dial until the black end of the magnetic needle points to “N” on the dial. Read the heading at the index line (which is the same as the direction of travel arrow).

Finding your location on a map

Place the compass on your map with base plate edge touching the first landmark (L1). Pivot the compass around on L1 until the orienting arrow or orienting lines align with the magnetic north lines on your map. Draw a line from the landmark (L1) along the side of the base plate across your map. Repeat this process for the second landmark (L2) and where the two lines intersect on your map is your exact location.

You Are Here!

I’m not sure why so many people struggle to use their compass correctly or just don’t bother to learn.  As you can see it’s pretty simple and the two techniques I’ve described above are extremely useful and important ways for you to determine where you are and where you should be going.  Hopefully this has helped some of you and for other it might just be a quick refresher course.

If you have any questions or suggestions on other ways to use a compass, please leave a comment on this post.

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  • Great post Brian.

    “Using a map and a compass is such a fundamental part of being outdoors or hiking that it should be one of the very first things that you learn before setting off to the wilderness.”

    Very, very true.

    Allan McDonald @
    EQUIPnTRIP

  • Pop quiz Brian! On a compass with a mirror, what is the true purpose of the mirror?

  • @Norseman: Ha, that’s a trick question! You want me to say that it’s for being able to view the compass dial and background at the same time so that the vertical line can be used to find a spot on the horizon and more accurately target my bearing – BUT – the true purpose is to help me apply my cammo grease paint neatly with even strokes on my face, right?

  • Great post Brian,
    Very helpful.

    Robin

  • Great informative post. Thanks for sharing.

  • Brian, no its so you can see who’s lost…

  • Great post, really helpful. We created a free interactive resource for teaching map and compass skills: http://www.cardinalpoints.co.uk

  • Thank you for a great article. Yes it’s true, a compass is a very important thing one should never forget when going outdoors to camp. If you don’t want to get lost, bring this.

  • Great post Brian. I wish everyone that depends solely on GPS would read this and get in a little bit of practice. I was just thinking today, as I was driving home from Indianapolis, that I don’t have paper maps in my car anymore, which is something I immediately plan on remedying as I have become too dependent on the nav system. Always a bad thing to do on the trail or on the road :-)

    Oh, and the mirror is for secretly peering around large objects, such as trees or boulders, and spotting Bigfoot without him being aware of your presence.

  • I agree with you. The basics of hiking includes compass and a map.Your post is very informative.This will help us especially new hikers to know the basics.

  • What a very informative blog. You have shared the importance of a map and a compass. I commend you for such a well constructed blog that is very useful to new campers and to the old campers as well. It is worth reading. I will recommend this blog to my friends.

  • Nice how-to.

    Just a quick note on declination: If you’re ignoring it, every degree of declination equals 92 feet of error over a mile traveled. That adds up quickly in areas with large declination.

  • @Bryan – That’s a great number to have handy in my head. “Every degree of declination ignored=92 feet of error over a mile traveled”. I wasn’t so much saying to ignore it, but for most people who are not traveling long distances it’s not normally a big issue.

    I was planning to write a follow up post to explain declination, how to adjust for it and why it is important to know about and account for – which you summarized in the single sentence above!

    Appreciate the comment and feedback, doing my best to make the posts useful for others.

  • Skills with a compass can leave you in good stead even if you don’t have a compass!

    If you know the time, the shadow from a walking stick will point east or west with variations for the season and put you on course within 10 or 15 degrees.

    Also, if you have a watch with hands you can figure out cardinal headings. Simply point the little hand at the sun and split the difference between the little hand and the noon (or twelve o’clock) position. This is your north/south line. Keep in mind the sun rises in the east and sets in the west. This tells you which end of the north-south line is north or south. Note if you’re on daylight savings time just use the 1 o’clock position.

  • Bill, I couldn’t agree with you more. In fact I am in the process of writing a three part series of posts to describe how you can reliably and accurately learn to navigate without the use of a compass – much like the methods you mention.

    Part one of this series (Navigating Using Stars) was posted a little while ago. Parts 2 & 3 will cover using an analog or digital watch and the basic shadow stick method.

    There are lots of ways to navigate without a compass, but knowing these three should provide a good enough backup in most situations.

    Thanks for the comments, hope to hear from you again soon.

  • I agree with you. The basics of hiking includes compass and a map.Your post is very informative.This will help us especially new hikers to know the basics.

  • Great informative post. Thanks for sharing.

  • Pop quiz Brian! On a compass with a mirror, what is the true purpose of the mirror?

  • Jim

    Brian,

    Thank you for sharing your knowledge.

    Jim

  • Jim

    Brian,

    Thank you for sharing your knowledge.

    Jim

  • the best way to adjust for declination is to position the map so that the orienteerring lines are pointing to magnetic north (ie. red in the shed). That way you don’t need to fiddle with the math of subtracting the declination from the compass bearing and it reduces errors.  

    • Ha! I wasn’t sure if anyone used that anymore. I was taught it as “..put the Red in the Shed and follow Fred!” Thanks Philip :) I think I’ll write that up for those that are not familiar with it.

  • the best way to adjust for declination is to position the map so that the orienteerring lines are pointing to magnetic north (ie. red in the shed). That way you don’t need to fiddle with the math of subtracting the declination from the compass bearing and it reduces errors.  

  • Ha! I wasn’t sure if anyone used that anymore. I was taught it as “..put the Red in the Shed and follow Fred!” Thanks Philip :) I think I’ll write that up for those that are not familiar with it.

  • Drmiczak

    Hi Brian, great information! I have two digital compasses from High Gear. Any tips on how to get the most out of them on the trail? Thanks.

    • In my experience watch based compasses are nearly worthless because they can’t be used to navigate (no orienteering lines)  on a map. The part that is worthwhile is the built in altimeter, but it needs to be carefully calibrated every day to factor out local changes in barometric temperature that are related to weather and don’t reflect altitude changes. 

    • I have to agree with Philip on this one. Digital watch based compasses are really only any good for basic bearing finding in my opinion. I’ve had several very good quality watches given to me as gifts over the years and have always been disappointed by the usefulness of the compass feature.

      Not only do you have to constantly re-calibrate the watches to have any form of accuracy, you also have to remove them from your wrist and ensure that there are no metallic objects in the nearby vicinity as they will throw off the reading your watch is giving you.

      I have no issue with anyone who wants to use a watch based compass as long as they are fully aware of the capabilities and limitations of what it provides. I would highly recommend that you look at supplementing it with an inexpensive baseplate compass.

  • Drmiczak

    Hi Brian, great information! I have two digital compasses from High Gear. Any tips on how to get the most out of them on the trail? Thanks.

  • In my experience watch based compasses are nearly worthless because they can’t be used to navigate (no orienteering lines)  on a map. The part that is worthwhile is the built in altimeter, but it needs to be carefully calibrated every day to factor out local changes in barometric temperature that are related to weather and don’t reflect altitude changes. 

  • I have to agree with Philip on this one. Digital watch based compasses are really only any good for basic bearing finding in my opinion. I’ve had several very good quality watches given to me as gifts over the years and have always been disappointed by the usefulness of the compass feature.

    Not only do you have to constantly re-calibrate the watches to have any form of accuracy, you also have to remove them from you wrist and ensure that there are no metallic object in the nearby vicinity as that will throw off the reading it is giving.

    I have no issue with anyone who wants to use a watch based compass as long as they are fully aware of the capabilities and limitations of what it provides. I would highly recommend that you look at supplementing it with an inexpensive baseplate compass.

  • This is great stuff Brian, we’ve just shared it to our customers. Thanks for a simple, straightforward guide /me doffs hat.

  • This is great stuff Brian, we’ve just shared it to our customers. Thanks for a simple, straightforward guide /me doffs hat.

  • Thanks Gareth. Did you post a link on your site somewhere or tweet it out? I’d love to be able to link back to it. ^BG

  • Hey Brian, just up on our FB pages last night but tweeted about it today as well. 
    https://www.facebook.com/webtogs/posts/180930968696920 

  • jkathleen23

    I would really like to know what your top ten items would be. I’m still reading your blog. I appreciate all of your wonderful ideas. Thanks, Helen

    • Helen, thanks for the kind words. Do you mean my top 10 favorite pieces of gear or my top 10 tips and tricks?

  • Nathan Enyart

    Brian excellent site. I am prior service, old school but still learning interesting stuff on here. I love the outdoors and going for hikes in big forest. This is very interesting

  • NoviceHiker

    I am a novice. I just finished reading/watching 4 different explanations for how to use a compass and map, and this is by far the clearest. Thanks!

    • Thank you for your kind words and for taking the time to say so. I aim to make the information easily understandable and usable, so it’s great to hear that it is helping and makes sense. Stick at it and make sure you practice. Many of the skills we learn as hikers are perishable – if you don’t use them you lose them! // Brian

  • Amie Colbert

    Wonderful post

  • Lucretia Rinker

    Great ideas – Incidentally , you are looking for a Petition for Commutation of Sentence , my colleague filled out and faxed a fillable document here https://goo.gl/wU9HLT