GPS units

An interesting article by Gavin Raubenheimer

www.peakhigh.co.za


GPS in the mountains- the myth exposed

Last year I was sitting at my desk working, when a distress call came in from a hiker in the Drakensberg. He reported that he and his wife had been lost for two days in a region of the southern area of the range and they were requesting a rescue. Some 48 hours earlier he had fallen down a small slope and in doing so his Global Positioning System (GPS) had got lost somehow. I went through the standard type questions on the state of the parties health and the weather and so on. What I soon established was that they had a proper map with them but they could not read it, so they could not work out where they were. Nor had they known for two days where they were. Even though the weather was clear the entire time!! More alarming was the fact that they had followed a single, large valley from the ranger’s office up until they lost the GPS, but they still could not find their way back. After a few minutes of questioning I established they were only a few kilometers from their car and I had field rangers sent out and they were soon brought back.

As head of a rescue team this is just one story of many that I have of non-existent navigation when people rely on GPS systems. Hikers and climbers have come to believe that the hand held GPS is the answer to bad map reading and the magnetic compass. People are still getting lost at the same rate as before, if not more often. They sometimes find themselves in an even worse position than they would have twenty years ago, simply because they cannot even vaguely read a contour-line or they aren’t carrying a map.

So why has the GPS become so ubiquitous in the mountains and wilderness areas of South Africa and around the world. That is a long answer but to try and explain it, let us examine what it gives us: The GPS can tell us where we are (most of the time), it has a map built in and way points can be programmed in before or in the field. It can also tell the user all sorts of other data, like how far you have walked and how high you have climbed in total. Then in-conjunction with this is the human fascination with technology, continued upgrades of interesting techno stuff and basically human laziness to think and research things. Lastly people have been led to believe by the manufacturing companies that in their product lies the answer to great adventures and easy navigation.

So where does it go wrong? Let us look at another technological innovation of the last few decades, the microwave oven. When these first came on the market four decades ago the word was out that they could cook everything in an instant, even controlled right down to the last second. Everything from boiling a cup of water, to cooking steak and baking cakes. And that is all absolutely true – you can cook just about anything in a microwave oven. Unfortunately many foods don’t do very well with this method! Do you really want to do your rump steak in a microwave oven? The same goes for navigation in the wilderness, a GPS can do many things, but not all of it very well.

So why doesn’t a GPS work as well as we expect it to work? The main reason is this: in order to establish the best route from A to B requires the hiker to read what the contour-lines tell about the terrain they will traverse over. Hand-in-hand with that goes the ability to stand looking at the contour lines and the actual terrain ahead and tie the two together. Then with this it goes automatically that the hiker knows in what direction they are moving in and where they are in relation to their surrounds.

On a GPS, the screens are simply too small and hard to see what exactly is going on with the surrounding topography. On a map all those little tight contour lines, rivers and symbols are telling huge amounts of important information and most of this is lost on the GPS user. As a result the GPS orientated hiker knows where they are – – – on a little machine, but the hiker has little idea of where they really are in relation to the surrounding mountains or what the ground will be like once they are walking over it. That means they have no idea of the safest or most efficient way between two points. The reader must also keep in mind that when hiking over unfamiliar terrain the best or safest route cannot be plotted on a computer back at home. The best way can often only be seen when actually standing on the terrain in question, and it could become evident that a new line has to be taken. This simply is not possible while following a GPS track on a screen. The GPS user is drawn to keep on a predetermined track because they simply cannot see what will occur if they veer off it.

Now if a hiker or climber can read a map properly it goes without saying they must know where they are. Good map reading means that even when visibility drops to near zero, the map user maintains where they are by using tools such as a compass, map and terrain evaluation, river flow direction and a whole host of other very easy and logical clues. 10112010_008

There is also a big safety compromise when thinking that a GPS is the number one answer to getting around. An example of this is if you are hiking up a snow filled alpine valley in mist and cloud following a GPS track. Unless you have actually taken a map and studied the contours, there is no way of telling where the most likely avalanche slopes would be found and how to avoid them.

A short story to consider: A few years ago I took part in a multi-day mountain bike event in Lesotho. We were all told to have a GPS in each team with the route already loaded. Instead, in our team we had a map with the route marked on it, and a compass. As we rode across the unfamiliar mountains the teams tended to stop at the same points and start to consult their little navigation machines. There was a lot of squinting into the screens and conversation like: “Guys we are about 50 meters left from where we should be and its says we have traveled at 16.25 kilometers per hour since our last stop”. That is useless navigation, but it goes on all the time with outdoor people.

What we could see on our easy to read contour lines, was things like what sort of valley shape we were going to travel down. We could look ahead and see things such as: in about 1.5 kilometers the path will run parallel to the big river and 2mm (about 100 meters) above it until it joins the tar road in 5 kilometers time. What we could see on the map at a glance and we could also see looking ahead on the ground. The result: we could put the map away and follow the path until we reached the tar road. The GPS people could not see that, they could only see a blip on a not-too-easy-to-see screen. Later that day some rider looked over at us and said: “Let’s just follow them, they seem to know where they are going”.

If you are a proud owner of a GPS don’t despair. They have a use, but it’s not in fine or efficient wilderness navigation. You can get interesting data from them like distance traveled or height gained. GPS’s are also very useful for a land surveyor, when they need to find a specific point in very uniform terrain like a single peg in a grassy field. For the rest of the time they are best left in your rucksack or at home. If you consider yourself a serious outdoors-person, your first port-of-call will be a good detailed map, followed by a compass and a fist full of skill. If you have a GPS maybe use it as a paper weight to hold the corner of the map down.

About the writer:

Gavin Raubenheimer is a professional mountain guide and instructor and is the convener of mountain rescue in KwaZulu Natal, South Africa. He has navigated with a map and compass through mountains and valleys of the Drakensberg, the European Alps, the Atlas mountains, the Canadian Rockies, the Andes, Jordon, Scotland, Kilimanjaro, Mt. Kenya and the Ruwenzoris of Uganda to name a few.