Sunday, February 24, 2013

Travel and Navigation - DK Richardson guest post

Travel and navigation

If you can't tell the players without a program, you'll find travel far more difficult without a map. I discuss common map products, then provide a listing of where and how to obtain free or low cost map products for your use. I'll cover compasses, and point you to free, on-line training sources for the use of your compass. While a GPS receiver is nice, it does have some real-world drawbacks - I'll discuss those drawbacks.

Just like at the ball field, if you can't tell the players without a program, you may soon get lost if you lack a map to keep you on track. So, let's start this discussion with - why have a map in your DIY disaster kit? Simple, you need one.

Why Maps?

If you're like most folks I know, you have a favorite route to get places. If asked to give directions, I suspect you'll use phrases like, "Turn at the gas station" or "Go two blocks past the school, then turn right." You drive or travel places everyday - to work, the grocery store, to see friends and even over the river and though the woods to visit grandmother. And for your everyday needs, it works great.

What happens, though, when the river overflows its banks and wipes out the bridge you always use? Where is the next bridge up or downstream? Is a ferry available? How do you even get to the next bridge? Where are the low spots most likely to get flooded when the river escapes its banks? Is there even a long way around to get home? Well, if you had the right set of maps, and understand how to read the maps, you would have a lot less to worry about.

What kind of maps?

There as many styles and types of maps - almost too many to list. So, for this we will examine just a few. Back in the day, gas stations would give away or sell at low cost a variety of travel maps. These provide a basic layout of a defined road system and give a general idea of distances between fuel stops or towns. These fill a legitimate need and for what they are, do a good enough job - if everything is going along 'normally'. Many do not show secondary roads and may have outdated information - nothing ruins your day like finding a bridge that been washed out for two years or a highway under construction stopping your journey cold. The older the map, the more likely you are to be surprised - in a bad way.

Several vendors offer trip planning services with current information and a map printed just for your trip. Many people find this service useful enough to support a minor industry. Other vendors offer travel guides that are updated yearly - one of the more famous travel guides is the "Milepost" magazine - it details, mile by mile, the ALCAN highway and several side trips. The magazine says it is updated yearly, but as with any published guide, it's best to check in advance for price and availability for lodging, repair services and so on. Businesses come and go all the time, so any published guide is just that - a guide, and the older it is, the more suspect the information within. "Lonely Planet' offers a series of guides that enjoy wide popularity. Are these guides any good for a disaster kit? I would suggest there are better products.

The better choice would be a Gazetteer for your State/Providence or a select series of topographical (topo) maps. The DeLorme series of maps are nicely bundled for each state and contain both topographical type maps and well the road system for major cities. Each book, or atlas as they are called, runs about 20 US dollars and for the information they contain, are a wonderful bargain. At 11 by 15.5 inches they are handy without being too large to handle. (http://shop.delorme,com) Each of the atlases has a key to explain the sometimes cryptic marks on the map.

A dedicated topo map of a specific area, usually sold by the US Geological survey (USGS) gives the most data at scales varying from 350,000 to 1 all the down to 24,000 to 1. Or put another way, at the 1 to 24,000 scale - One inch equals 2000 feet. The maps are sold by Quadrangle and section - they may also be referred to by how many minutes they cover - that is 7.5 minutes, 15 minute and so on. USGS map products do show cityscapes, but as with most any printed document, can suffer from lag time to print - and therefore may be less than accurate in a fast growing area.

( to order maps from the USGS)

The more development in an area, the more all maps suffer from this lag.

To obtain free (and current) USGS topo maps go to - and select the map for your area of interest. You can print these at home, but I must warn the scale will not be exactly as listed owing to how your printer works.

Are you kidding me? Free maps?

Yes, indeed. Your tax dollars at work. They are free because you print them out. If you want a maps that the scale matches the printed product, then order the paper product from the USGS, the instructions are on the same page. About 10 dollars per 7.5 minute map.

Will this work for everyone?

The free maps download to your computer as a .pdf product. It will work as well as any other (large) .pdf. Be warned, most files start about 18 Megs in size, not for the faint of heart or those with dial up modems.

What if I don't have a printer or want a full scale map?'

Stores that sell and service drafting plotters often offer a print service for customers take your .pdf file down and see if they will print for you - expect to pay for this. You may also have you map printed on opaque mylar or Tyvek, both offer a durable and water resistant product. Finally, outfits like REI offer custom printing of maps for a reasonable fee.

I use (brand name) maps on my (iphone/android phone/gadget) - why should I use USGS maps.

The USGS is the standard for map accuracy.

What's will all those lines? Are they of any use?

That data, those lines, are what make topo maps so valuable. The USGS page has an explanation of what each line represents. This is both on-line and too long to cover here. Go, read, learn.

What is a compass and why do I need one?

For a quality topo map to be of the most use, it should be oriented - that is to say, lined up north to south the way it is drawn. This alignment makes it easier to relate terrain features you see to the map in front of you. To navigate - travel - using a map as a guide, a compass is a necessary tool.

What kind of compass?

There are so many different kinds and styles of compasses, from cheap button compasses to pocket transits costing several hundred dollars - the new user can get confused. Let me list a few simple things to remember -

-Real Quality costs real money. There is a reason that 'Chinese marching compass' or 'military style' compass will not work as good as a US made, milsurp prismatic compass - Quality. That is why one is 5 dollars and the other is 60 dollars. Just as there is no free lunch, there is no 'cheap and accurate' compass. The world doesn't work that way.

-The 'best' compass is one you know how to use to get the most from your map. Each compass has a purpose - so a hand bearing compass works differently than a Pocket Transit - both can be used to navigate. I'll narrow this down in a bit

-If you will use the compass in North America, buy one made to work in North America.

-In my opinion, a compass that will allow you to set declination (offset between the real GeographicNorth pole and the Magnetic North pole) is a worthwhile extra cost feature. You will make fewer mistakes.

-A compass that has some kind of sighting system will allow you to navigate more precisely.

- get a compass marked in degrees unless you plan on running a field artillery unit. (360 degrees vs 6400 mils)

So, now what? So - lets look at a very expensive compass - and some better suited to your kit.

This is a Brunton Pocket Transit. Arguably the most accurate hand-held compass you can buy - and at several hundred dollars, it is certainly expensive. While in college, I worked for a GeoEx company and we used these Pocket Transits to lay out mining claims. I would love to have one for the cool factor, but it is serious overkill. What's next?

This is the face of a Cammenga brand military prismatic compass. Cost - about 60 dollars or so. The dial is marked in degrees with reciprocal bearing in red, the needle is glow in the dark and as you can see, East and West are highlighted. The outer dial is marked in one degree notches, so you can use it in the dark - but why would you want to?

An excellent bit of kit and well worth the money. Okay for your kit, but still a bit of overkill. What's next?

The Silva brand "Ranger' compass. Listed at 51 dollars on the Silva website.

Rugged, has a sighting system, can be used to quickly orient you maps and has map scales on the base plate. Huummm, almost prefect. This model allows you to dial in the declination. And then?

The Silva Guide model 426 - ahhh, just right. About 15 dollars on-line. Comes a variety of colors, and it floats. The sighting mirror has a Vee notch at the top of the mirror’s sight line. The compass needle itself is made out of tungsten steel with a friction free sapphire bearing -so it moves freely. The compass is filled with clear antistatic liquid, so no annoying bubbles inside the dial or needle flutter. You can fold the cover back behind the compass if you want it be out of the way, say, while using a map. 2.5 inches square, it takes up little space. Did I mention, it will float? The dial is divided in 2 degree increments.

There are other compasses out there. Well made and a quality product. I've been using Silva and Suunto products for over 5 decades and they have never failed me. I'm writing this, so it is my recommendation. You can make your own choice, of course, but please take the time to compare features and quality, and then worry about the cost. Because if your cheapo compass fails or is inaccurate, how big a bargain is it in the end, really?

Okay, now you have a compass - how the heck do you use it? Books have been written on this, so I'll point to several on-line resources and let you pick the one you find easiest to understand.

Field Manual 3-25.26 Map Reading and Land navigation. The Army way of using a compass. A good read covering all the basics, and them some. Features a prismatic compass as seen above


A series of lessons on orienteering, a kind of race requiring navigation to precise locations. An oldie but goodie


Easy to read illustrated guide for the beginner or advanced field person.

Short version for folks wishing to brush up on old skills.

The only way to be comfortable using a compass - is to use one. Buy a map of your local area and then use the compass that will go in your kit to navigate from point to point! It can be a fun family activity. Try it.

Is a (brand name) compass better then...

Some compasses are priced higher than others. More money doesn't always better quality, but Quality does cost. Sapphire bearings cost more than those without, and so on. There are a number of Indian knock-offs of the Brunton Pocket Transit made of brass that are great paperweights. I'd never count on one to find True North.

Do I really need to orient my map?

When you are doing so-called paper exercises, planning, measuring distances, identifying hazards like low lying areas - no. In the field using the map to get from Point B to Point B, I would argue that you do need to orient the map for best results. Terrain features may look the same as another if you aren't sure of you exact location.

I don't need a compass, I have a GPS!

I'm happy for you. Most GPS units offer a heading feature - acting like a compass. I know the compass I use is accurate to + / - 1/2 of one degree. What about your GPS unit? Good luck on finding that information for your unit. I have a nice GPS unit and have used it when going photography overseas for industrial operations, marking the place I captured the image in a database and log. This is different that land navigation.

Are you saying a GPS is no good?

I am saying - be careful.

Printed maps and GPS coordinates may not agree - some map products - mostly outside of North America anymore, may be 'off' by upwards of several miles - the older the map data, the more likely this is to happen. This is because some products are using data obtained before the GPS system was in place - I have maps based on 1950s data - the data on the map is good - mountains haven't moved, but the geophysical coordinates don't match up to my GPS - owing to systematic errors from back in the day.

You've heard to the stories of people blindly following their in-car 'navigation system' and driving into lakes, rivers or even the ocean. A map requires a bit of care and should always be considered an aid to your travels. The older the map, the more care should be exercised, items build by man may be removed by nature, so any map you use to navigate from your home to a place of refuge should be vetted.

Pick and drive your alternate routes at least yearly. City road maps should be replaced on a regular basis, especially if you live in or near a fast growing area. Use your maps in advance to find choke points - bridges or overpasses/railroad bridges that could collapse and block the roadway. Mark and know the low lying areas that may be prone to flooding.

Thank you, Mr. Richardson, for this excellent information.  We are fortunate to have you share your knowledge with us.
Please leave comments or questions below, or email them to
Susan and the Poverty Prepping team


  1. I was just thinking about compasses yesterday. I don't have gps and might not want to count on it in an emergency if I did. Good, straight-forward post.

  2. Thanks Lawana.

    I'm editing the book version now - a book with lots of photos. I hope you'll find the book interesting as well.

    Thanks again