The Global Positioning System and Its Place in Wilderness Navigation

15 September 2009

Those readers who have perused our blog posts and the Desert Explorer Navigation Pages may have noticed the limited references to the Global Positioning System or GPS.  I do not write much about the GPS mainly because I do not use one for daily navigation, and do not recommend them as a primary method of navigation for foot travel.

I am not shunning the technology entirely- the GPS is a useful tool.  It has applications as a navigational aid- I purchased my GPS to use while working as an archaeologist, I have used a GPS in a vehicle while navigating the streets of unknown cities, I use mine now to log back road travel and to mark campsites and trailheads from my truck, and my son and I use it for finding Geocaches. But for foot navigation in the bush, the GPS is secondary to the map and compass. Navigation is done with a map and compass and there is no substitute for knowing how to use them.

For most people I encounter using a GPS, it is merely another toy, not unlike their iPhone or Mp3 player.  This is true of people I see on the local trails when I run, people riding around the park with their bike GPS units, and even people I encounter on top of Colorado’s Fourteeners (peaks over 14,000 feet in height). In these cases the GPS is not necessary, but merely a diversion, and at this point it is not a danger.

But the GPS can and does get people into trouble.  Time and time again, on nearly every trip I make, I run into confused and misoriented (see the 24 April Blog post for more on misorientation) people in the bush, “navigating” with a GPS, who ask me to confirm their location. I have helped off-roaders find their way back to pavement, ATV’ers find where they parked their trucks, and pointed hikers back to trailheads. Each time I wanted to ask these people if they had a compass, or even a map, let alone the knowledge to use them. And have they even read the instructions for their GPS unit? In all cases I pointed them in the right direction and let them go.

A recent experience on the Escalante River further supports my advice against the GPS. While Robert and I were at the mouth of Fence Canyon we ran into a backpacker who, with two others, had hiked in during the night.  They had come from a trailhead less than 5 kilometers away using their GPS to guide them to their destination.  They came in about midnight and stumbled around the mesa top for hours before finding their way into the canyon, walking miles more than they needed to. The moon was nearly full that night, and a 100 year old cattle trail led from the trailhead into the canyon.  It is probable that my five year old son could have followed that trail.

None of these people were navigating– they were busy looking at their GPS screens, completely unaware of their location on the ground, of the terrain around them.  According to the American Heritage Dictionary to navigate is to plan, record, and control your course and position. In my examples above there may have been some planning, we assume the GPS recorded, but there was apparently no control of the process of navigation. This is a problem. And this is my main argument against the use of GPS units as a primary method of navigation. If a person lacks the knowledge to use the GPS properly, that is bad enough. If they cannot navigate without it, this is even worse.

Further arguments against the GPS, especially as an ultralight backpacker are the weight of the units, and the weight of extra batteries. And batteries can die,  electronics can fail.  Remember too that satellites can be shut off- recall that this happened to the Global Positioning Satellites in September of 2001.

To avoid the problems that might be caused by a non-fucntionaing GPS, dead batteries, or the lack of knowledge of the unit, anyone venturing into the bush should be carrying and be able to navigate with a map and compass. There are plenty of great books explaining basic navigation, most of them presenting too much information.  The average person really doesn’t need to know about polar coordinates or the vairous projection systems.  But they do need to know about declination and topographic features. The Desert Explorer website presents basic navigation on the Maps and Navigation pages. There is no substitute for navigation skills, to becoming a competent navigator, and reliance on technology does not build these skills.

Gear Reviews- Sea to Summit, Sealline, and Dry Pak Bags and Cases, Merrell Water Shoes

7 September 2009

In a recent post I mentioned a few new pieces of gear that Robert and I used on our recent trek along the Escalante River. All the new gear had to do with water- waterproofing and walking in water. This included a Sea to Summit Ultra-Sil Pack Liner and Dry Sack, a Dry Pak cell phone case, a Sealline HP map case, and the Merrell Waterpro Maipo water shoes. In this post I will give a quick review of each piece of gear.

Sea to Summit Ultra-Sil bags- Sea to Summit makes a full line of Ultra-Sil Dry Sacks and Pack Liners, and medium-weight and heavier-weight dry bags with various features including air evacuation material.  The bags are available from REI (Pack Liners are available online only), and at Amazon through the links below where they can currently be found a bit cheaper.

STS_packlinerIn a word the bags we used performed perfectly.  Knowing that my gear was safe and dry was worth the extra 4 1/2  ounces that both bags added to my overall pack weight. I used a 50 liter Ultra-Sil Pack Liner, which stayed in the bottom of my Golite Pinnacle pack and had gear packed into it. The 50 liter, their small size, weighs 2.6 ounces and costs about 35 dollars at Amazon or REI. The small is available in orange only. The medium, at 70 liters,  weighs 3.4 ounces, comes in green and costs about 28 dollars at Amazon (lowest price).

STS_drybagOver top of that I packed a 20 liter Ultra-Sil Dry Sack, their extra-large size, which I used for all of my small gear, maps, daily snacks, and essentials.  The Dry Sack came out of the pack for easy access to gear.  The two bags together were perfect for organising and packed easily.  I was in deep water a number of times with the pack submerged and there was no indication that water got into either one.  Of course this has to do with how you pack them- packing gear snugly inside, removing all the air, and rolling the tops tightly is essential to their function.

The 20 liter bag weighs just 1.8 ounces. It costs about 23 dollars at Amazon or REI, although is cheaper at Amazon if you order the orange color.  These bags are available in sizes from 1 liter up to 35 liters, and range in price from about 11 dollars to 25 dollars at Amazon.

The bags are very thin silcloth material and are light in weight. They were perfect for this type of trek. If you plan to be in water beyond an occasional quick swim across a deep pool, such as while canyoneering, you may want to choose something a little more substantial.

Sealline HP Map Case– If you are looking for a map case, look no further. This map case tops my list as my favorite over the years- and I have carried many.  Most recently I have been using freezer weight, one-gallon Ziplock bags as map cases.  These are a great choice for general hiking, but the Escalante with its possibility of swimming at any moment demanded something more secure.

The Sealline HP Map Case is made of very thin urethane material that is strong enough to survive hanging out of your pocket while bushwhacking along the Escalante. The material is crystal clear, the map inside is easy to read. I hope it stays this way- the previous version of the HP map case yellowed and hardened with exposure to the sun. The new version is a completely different material and I think this is one of the reasons for the re-design.

sealline_caseThe new version, just out this fall, has a roll top with a velcro strip that holds the roll tightly together.  I had the case completely under water many times and only once, after a long wade across deep, fast water, was there the slightest bit of moisture in the outer-most roll when I opened the case later.

The case has two buckles and a strip of web to hang around the neck. I removed the web and ran a piece of 550 cord through one of the loops to secure the case to my belt loop.  The case also has 4 tabs, one in each corner for tying onto the deck of your kayak perhaps, or the pack of the man in front of you. As I would never use them, I cut off the tabs straight away (extra weight).

The case is available at Amazon in two sizes, small and medium, at 25 and 30 dollars respectively.  There is also a large size that I have only seen at  They are not sold at REI yet, but should be in the future. (REI sold the older version of the cases.) The small case weighs 2 ounces, the medium 2.5 ounces, and the large weighs 5 ounces. Inner dimensions are 9.5 inches by 12.25 inches for the small, 13 inches by 15 inches for the medium, and 14 inches by 21 inches for the large.

The small size accepts a USGS 1:24,000 mapsheet with the margins cut off. The mapsheet can be folded in half on both axes and slid right into the case. See the 11 January 2009 blog post for more on how and why I trim maps.

Dry Pak Cell Phone Case– This was my first experience with Dry Pak cases.  I needed something for my point-and-shoot digital camera. The Dry Pak Cell Phone Case was the perfect size.  The case performed as I had hoped, keeping the camera clean and dry, and providing a little bit of padding (designed for flotation). The only drawback is the closure-  it is a bit bulky with hard plastic strips at the top and two button closures. Once twisted to open, the button closures could, if pushed the right way, come out of the plastic strip and be lost. They are secure when new, but may be something to keep an eye on once the case is well used. I was worried that the bulk of the closure strips might be awkward in my pocket. But I did carry it in my shirt pocket and it was fine, being no thicker than the camera that I put inside it.

drypak_caseDry Pak cases come in many shapes and sizes to fit nearly any piece of electronic equipment.  All appear to use the same closure device. The Cell Phone Case comes with a lanyard and small snaplink, both of which I removed immediately (extra weight).

The small case which I used weighs 2.4 ounces and is 4 by 6 inches in size.  The material and the seam welds seem strong and durable.  I am guessing I will be using it on many other trips.

Merrell Waterpro Maipo Water Shoes– The final piece of new equipment on the trip was the Merrell Maipo water shoe. Both Robert and I used these shoes, and both of us returned them after the trip because of broken straps. We only put about 70 miles or so on the shoes and expected much more out of them. Since returning them, I noticed that they are no longer available at REI.

In my search for water shoes I read a bunch of reviews and concluded that none were very well designed, at least for our purposes. I ended up choosing the Merrells, based on the fact that they were one of the fullest shoes available, they were light weight, and because of my own positive experiences with Merrell products. I own two other pairs of their shoes at present and have never had an issue with these or any of the many other pairs of Merrell shoes I have owned.


Merrell Maipo water shoe

After using the Maipo shoe I can say with certainty that they need more design work.  The small straps wrapping all around the shoe, while they may add some support and a little bling to the shoe, are a very poor idea for many reasons. The straps are only about 1/4 inch in width. These straps wore through, broke in half, in two locations on my shoes, and the cord that the straps wrap around (near the bottom of the shoes) broke on Robert’s shoes.  On both of our shoes the straps and cord were wearing through in other locations.  I ended up tying the broken straps together to restore the support they offered, and to allow the laces to function (the laces run through these small straps at the top of the shoe).

Beyond the strap issue, the shoes were comfortable, as all Merrells are. They drained well; the mesh is large enough that it drains quickly, but also large enough to allow sand into the shoe.  I think this may be the case with any water shoe that has good drainage.

Merrell Ottowa water shoe

Merrell Ottowa water shoe

Merrell makes another water shoe similar to this one, the Ottowa, seen at left.  I have not used this shoe, but it seems to be a better design than the Maipo. On this shoes they only have the problematic strap at the top of the shoe. There is no cord through it to cause friction and wear through- the laces run through a plastic eyelet.

The mesh seems to be the same however, and there is more of it exposed.  You may end up with more sand in these shoes than the Maipos. But I am sure they would hold up better in the end. You can read more about them at And if anyone from Merrell happens to read this review, I would be happy to try out a pair of the Ottowas and write about them. I am heading back to Utah in early October for a canyoneering trip in North Wash and will need a good pair of shoes.

For more information about our walk along the Escalante River, see our 22 August blog post or the Escalante Trip Pages at the Desert Explorer website. For more on the gear we use and ultralight backpacking, visit our Ultralight Pages.