April 2008 was a very interesting experience for me, not only in terms of the new places visited and the demands of the poor weather, but also the necessity to navigate to a high degree of accuracy in little or no visibility on a frequent basis. Thanks to Adam Wainwright for the photo from yet another white out day in the Silvretta!
The map came out every day, just to work out which col to go over, even when we could see.
The compass was out almost every day as we were frequently in white out. I often found myself snowploughing on a bearing for 50 to 100 meters, stopping, taking a back bearing on the vague outlines of the group in the mist behind, and then having them ski directly to me before repeating the process. It's slow and tedious, but keeps me on the bearing and gives the group a visual frame of reference to ski with.
The altimeter on my watch was used most days too, as it's difficult to keep track of distance otherwise, particularly when skiing downhill. With frequent recalibration at known points such as cols or buildings, we were kept on track and when necessary I could pinpoint our position to within 50 meters at any time.
I used the GPS as a validation of that technique rather than as a first line of attack. I think it's an important distinction, as there can be a temptation to rely on the electronic box of tricks, and forget traditional navigation. This is a dangerous attitude for 2 reasons:
- What happens if the GPS batteries run out and you've not been keeping an eye on your position on the map?
- There's a tendency to ski along with your eyes on the screen instead of looking around for landmarks, crevasses, avalanche slopes etc.
On one quite bad day, I was asked by another team of ski tourers if I thought it was safe to cross over to the next valley. I replied that it would be, providing they had the physical strength to trail break in the deep snow, and could navigate accurately. Their reply was "oh, it's OK - we have a GPS". That's NOT what I said, I thought to myself, but restrained myself from making a comment.
In the words of Martin Epp, a legendary Swiss guide:
"We use GPS to get out of ze bullshit, not to get into ze bullshit"
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