Positioning System (GPS) receivers has simplified navigation to an extent but the knowledge of how to use a compass is still important; do not underestimate this skill.
- They are declination adjustable
- Liquid filled housing to dampen the magnetic needle’s movement
- 2° increments on the bearing dial of the compass housing
- A clear baseplate of adequate size with map scale information and a small magnifier.
- Using the owner’s manual, adjust the compass for declination.
- While holding the compass at waist level, turn squarely towards a distant object. Hold the compass so that the direction of travel arrow points directly at the object. (Point the direction of travel arrow away from you; perpendicular to your body.)
- While holding the compass, turn the compass housing (the dial) and align the orienting arrow (engraved in the rotating housing) underneath the red magnetic needle.
- In this example, the compass has been adjusted to a bearing of 011° degrees. The bearing data is found where the direction of travel arrow intersects the compass housing.
- Identify three distinct objects to sight on. Note that the objects need to be on the topographic map (topo) of the area. I recommend carrying a forest service map (or something similar) of the area in addition to the topo just incase the objects are too far away.
- Orient the topo using the compass. Orienting the topo means that the map’s left or right border is pointing to true north or 000° degrees true. See “Orienting a Map” for more information.
- Sight on an object such as a mountain peak or church spire. (Note that not many objects in the backcountry are so distinct and crisp. Do the best with what you have.) Ensure the direction of travel arrow is pointed towards the object.
- As discussed earlier, turn the compass housing until the orienting arrow is directly under red magnetic needle. Do not move or rotate the compass housing, keep the new bearing in place.
- At this point, and while plotting the bearing on the map, the compass will now be used like a protractor.
- Lay the compass on the map with either the top left or right corner of the baseplate on the landmark. This will be a pivot point while aligning the compass.
- With the edge of the baseplate in position, rotate the compass (swing) left or right until the N (north) of the compass housing aligns with map North (the top of the map.) What is even better, with the map oriented to north, as the baseplate is rotated, the red magnetic needle will swing back into position on top of the orienting arrow.
- Draw a line (along the baseplate) from the object to your approximate area.
- Repeat the process two more times.
A trail is highlighted in the map above. Trails are black dashed lines.
Topographic map users are familiar with the small diagram at the bottom of the map.
The graphic and information presented relates directly to the declination of the map area, orientation of magnetic north, orientation of grid north and true north.
represent township and range. The red numbers refer to each of the 36 sections found in a township. (A section is a square that is one mile by one mile on each side.) Determine if these red line are oriented to true north in advance of your trip.
The line with the partial arrow head points to magnetic north (MN.) Without getting bogged down in the pole’s location, the key thing is to understand is that magnetic north is what a compass’ red magnetic needle point to. The numerical value of 19° refers to the declination; the angular measurement between true and magnetic north. In this case, the declination is 19° East. It is this value that the hiker will compensate for in navigation.
Reviewing a topographic map is usually the starting point for the planning of any back country trip. A topographic map is your road map to the outdoors. It provides you detailed information at a scale that is meaningful and detailed. For years, the US Geologic Survey (USGS) has been the principal publisher of accurate maps. Within the last decade we have seen many innovations in mapping products that include new mapping companies and publishers, software, maps for the GPS, and “Apps” for the iPhone.
Still, the USGS map remains the standard for back country navigation (visit the USGS’s site at www.topomaps.usgs.gov.) I’d also recommend looking at June Fleming’s “Staying Found” or Bjorn Kjellstrom’s “Be Expert With Map & Compass.” Once you develop a map foundation you will easily shift to many of the other products on the market today.
Many publications, videos, and web sites will give you a te rundown on the features, symbols and components to a map. This article will discuss a few of the key features that you should be aware on a 7.5 minute map.
· Contour Lines These are the thin brown lines that snake across the map. Contour lines connect equal points of elevation such that every point on that line will be at that elevation above sea level. Visually, the contour lines give you a mental three dimensional view of the terrain. These lines provide a view of slope and pitch, depressions, ridge lines and level ground; the highs and lows of the earth’s surface.
These lines provide shape and a sense of texture. There are two primary types of lines, index and intermediate lines. Index lines stand out as they are a touch wider, a darker shade of brown and indicate the elevation with numbers such as 4500; the elevation is in feet. Between the index lines are the thin intermediate line that are spaced uniformly and further define the elevation, slope and contour. The intervals between the intermediate lines are specified at the bottom of the map adjacent to the scale data.
· Scale Consider scale as your view of the map; it is like your “overhead zoom” setting. To cut to the chase, a 7.5 minute map or quadrangle has a scale that is referred to as 1:24,000; where one inch is equal to 2000 feet. It is your best source of information of the back country. At this scale, the map has much more validity and provides more usable information for your backcountry planning. You can view important landmarks, streams and geographic features. To complete the navigation picture I always refer a second map, such as a map of the national forest (e.g., the Deschutes National Forest.) Commonly, such a map will be “zoomed” way out and have a scale of 1:100,000 or 1:250,000. Imagine that such a map would be made up of many 7.5 minute quadrangles.
· North Features on a map such as trails, roads, mountain peaks and streams are all laid out in relation to true North; the North Pole. The north-south borders of the map and the small declination diagram are your best references for true North. Other grid lines (such as the red Township, Section and Range lines) may not be aligned to true north at all. Be careful of these lines should you need to triangulate your position on a map.
· Declination This is the angular difference between true North and Magnetic North. The red needle on your magnetic compass points to Magnetic North. The accuracy of the information found in the Declination Diagram is dependent on the age of the map. To get the latest declination for any area visit www.magnetic-declination.com.
Personally I use a magnetic compass that I can adjust for declination; it just makes my navigation easier. When adjusted, my compass provides bearing information in degrees true as does my map and my adjusted GPS.
· Coordinates Latitude and Longitude (Lat/Long) are the familiar coordinate system to most outdoorsmen and women. Coordinate data is found at the top and bottom corners of each map. Lat/Long coordinate increments are also found every 2’ (minutes) and 30” (seconds) on the sides of the Map. A scaling device is necessary to pull complete coordinates off a map; this is a pain.
In the 1940’s a coordinate system know as Universal Transverse Mercator (UTM) was developed. To keep a very long story short, your 7.5 minute map has a new grid laid over it, the grid dimensions are 1000 meters by 1000 meters. For more complete information on UTM grid visit the USGS’s web site UTM or Lathem’s “GPS Made Easy” (which is probably at your local library.)
Simplicity is the essence of UTM. Scouts, hunters and hikers have joined Search and Rescue (SAR) teams around the country in using this system.
Your GPS receiver can easily be switched to UTM from the set-up menu.
· Bar Scales Notice the bar scales at the bottom of the 7.5 minute map. The scales provide measuring data in miles, feet and meters. On the far left side of the meter scale, the scale is broken down into units of 100 meters, this applies directly to UTM.
Notice on the scale bar (feet) that 1 inch equals 2000 feet.
· Map Datum Information about map datum is found in the lower left corner of a 7.5 minute map. I have found that the simplest definition from GPS maker Garmin is:
“A math model which depicts a part of the surface of the earth. Latitude and longitude lines on a paper map are referenced to a specific map datum. The map datum selected on a GPS receiver needs to match the datum listed on the corresponding paper map in order for position readings to match.”
The bottom line: most 7.5 minute maps are made to the North American datum of 1927 (NAD27 or NAD27 CONUS on your GPS). New GPS receivers are set to datum WGS84. The difference between the datum could be over 100 meters/yards. The solution: When pulling points off a map shift your GPS’s datum to match the map.
If precision is not an issue for your outing don’t worry about datum.
As you begin your trip planning don’t forget the magnetic compass, the important partner to any topographic map. See Selecting a magnetic Compass for more information about buying a good compass.
Looking for a good overview of map and compass basic procedures. Take a look at United States Search and Rescue Task Force’s post on map and compass basics. The following is a excerpt from this site:
“A topographic map tells you where things are and how to get to them, whether you’re hiking, biking, hunting, fishing, or just interested in the world around you. These maps describe the shape of the land. They define and locate natural and man made features like woodlands, waterways, important buildings, and bridges. They show the distance between any two places, and they also show the direction from one point to another.”
|What should the hiker consider regarding night time travel in the backcountry?
First, let us decide that this is not in a “lost hiker” scenario. If lost, the best thing to do is to
just stay in place. This makes the job much easier for the searchers.
At night the term used to describe our ability to see is “night vision.” Good night vision is important. Therefore, avoid bright lighting. Flashes of bright white light will ruin night vision. Recovery can take about 30-45 minutes. Low level white light and low intensity red light are better.
Care should be taken with the use of a GPS. The normal white backlight function of the GPS receiver will impair night vision. The good news is that the backlight can be adjusted.
Here are a few recommendations:
Night time navigation is not something to be taken lightly. From reviewing my books, US Army field manuals and conversations with experienced backcountry travelers it should be carefully considered and practiced before an actual outing. Practise your navigation at a local park with map and compass. Consider geocaching to improve your GPS skills.
Not selecting the correct map datum could induce an error of over 100 meters/yards. I emphasize that hiking groups should all be on the “same page” regarding the set-up options of their GPS receivers.
While planning a journey or at the trail head, taking the time to adjust settings among hiking partners is critical. Before departing, validating map datum and coordinate format should be a priority.
First, match the map’s datum. A topographic map identifies datum in the map key. Once the datum is identified ensure that all GPS receivers are set to match the correct datum. See the illustration below.
For more information on GPS setup setting check out:
Improving GPS Accuracy, Setup Your GPS
Last week I was lucky enough to get the opportunity to put three products through their paces while on a military land navigation course. While I’ve owned them all for a little while now it felt like this was a chance to solely focus on how well they helped (or hindered) me when it came to accomplishing a GO/No-GO task, this versus toying around with them while on any old trail. I’ve written about how much value I put in great shoes/boots (specifically the Salomon’s), the same for my Eberlestock pack and I may or may not have touched on the MilGPS app available for both the iPhone and Android devices.
The Task: Land Navigation
I’ve been walking land navigation courses with a map, compass and protractor since I was in JROTC in the early/mid 1990’s. Anyone remember Tenino, Washington? Where is the water tower? Sorry…inside joke. Last week’s land navigation course would be an intermediate course by my standards, not an overly difficult tast but the elevation changes/underbrush and wait-a-minute vines were slightly annoying. I should add that while I do value old school land nav and think it’s a great skill for any prepper and not just the military types, this time old school would take a back seat to technology. I needed to find out if the MilGPS app was legit and could be relied on even with the cell signal fading in and out. I also needed to shun standard mil issued gear for my own swag which often results in one wondering how in the world aftermarket gear can be so much better than issued stuff, but I digress.
Salomon Boots: Just ridiculously good.
First up were the Salomon boots. I’ve been wearing them casually to work and for some light hiking but nothing like what the land nav course would offer, additionally I’ve yet to wear them while carrying somewhere in the neighborhood of 60lbs on my back. To complicate things a bit more I’ve been fighting a very sore/tender Achilles tendon for a few months, a byproduct of age and trying to sprint out of the batter’s box during a beer league softball game.
The boots (paired with Smartwool socks) performed flawlessly all day long under all conditions. The footing was uneven and unpredictable for most of the day and the ankle support provided by the boots was superb. Descending into dry river beds or climbing up the side of steep spurs did not present an issue either, grip was fantastic and support was there. My foot did not move around inside the boot and that was definitely a bonus, if you’ve ever had that happen you’ll know it can get very annoying. No hot spots during the entire event and my feet were able to breathe quite nicely. Great boots overall although a longer term test might reveal some shortcomings.
Eberlestock V69 Destroyer: Amazing.
You don’t know what you don’t know, a saying that originated somewhere but has since been repeated through the years. I’ve always been a staunch supporter of the old school ALICE pack and had even continued to use that after being issued the newer model. Yet even with aftermarket shoulder straps and other additions the ALICE pack is like a rusty Ford Pinto when compared to a new supercar: the Eberlestock pack. As a veteran of many, many movements under load I know how the discomfort starts to set in and how to deal with it while wearing an ALICE pack. I can assure you that NONE of this was present while wearing the Eberlestock pack so much so that I wore it all day long. I never took a moment to drop my pack for a breather, I just motored on because the level of comfort was simply amazing. No pressure points at all, it was like the pack was part of my body and moved with me. Truly I believe the combination of their internal frame design, waist strap and shoulder straps really contribute to a world class experience for the wearer. I should add one caveat in that while it was a long day it was only ONE day. To truly get a feel for this pack I would have to wear it every day for a few weeks, so take that in consideration with my endorsement.
You’ll notice in the picture that I have my tent strapped to the outside of my pack, that’s because I took it out to make room for my Kelly Kettle. Look for a review on that soon although The Maj used it with great success on his bugout journey last year.
MilGPS App: Surprisingly Good.
I can hear almost any instructor ever in the history of land navigation right now: “all those gadgets are great but if they fail what will you do then?” I get it. I GET IT. It’s great to know the old school methods but let’s face it, technology is here and the MilGPS App can be a great addition to any prepper plan of action.
I will admit that I did plot all of my points and kept my grids, distances and directions just in case while out on the course but I absolutely did not need them. I punched in the 10 digit grid on my app and hit “navigate to” and just followed the arrow. I saw the distance, direction and in every instance the app brought me to within 10 meters of the point. If there were instances when I did not want to break brush I would skirt it via a ridge line or riverbed and just cut through back to the point when about 100 to 200 meters away. It was excellent and there was no remembering pace count, trying to box obstacles, shooting azimuth’s with the compass. Just type in the destination and start walking. Bingo.
Now I do understand some of the constraints associated with using an app like this. You’d better have a good battery and a way to recharge your battery if out in the woods. While having a cell phone signal is nice according to the developer it isn’t exactly required. Also if you don’t know how to utilize the military grid reference system or have access to maps with that date, that could be a slight problem. More info here under the Land Navigation category of this blog.
I’m not sure how many times I’ve stated this before but you must get out and test your gear in the field. It doesn’t even have to be a week long excursion deep into the Rocky Mountains, maybe an overnight hiking trip or even an all day through your local national forest. It’s at that point when theory turns into practical application, when that fancy piece of equipment starts rubbing you in the wrong spot or doesn’t work as well as you thought. Or maybe you’ll find ways to reconfigure your gear based on how you utilize it, or in many instances you’ll figure out that you can leave certain things home next time.
Nobody says you have to run out and drop $500 on new boots and a new bugout bag which you may or may not use in the next 6 to 12 months, but if you do decide to upgrade you really can’t go wrong with the items I’ve reviewed above. The good news is that the MilGPS app is relatively inexpensive, so start with that!