The sun gradually disappears behind the peaks. The last rays come to warm the fresh air of the plain below, covered with snow. In this lost corner, somewhere, away from the slopes of the small resort of Ceillac, at the gates of Queyras in the Hautes-Alpes, one expects to come across a reckless skier, in sealskin, or at least a black grouse lost in this frozen desert. But on tiptoe, flippers in the baths, we see in the distance strange amphibians carefully treading the frozen ground of Lake Sainte-Anne, at an altitude of 2,300 meters.
On this January morning, at dawn, at a time when the countryside was whitening, the gendarmes of the river and nautical brigade of Martigues left, leaving their Mediterranean Sea to practice diving for the first time. under ice. A situation that these specialized gendarmes must be able to master, in particular in order to be able to find a skier trapped in this frosty prison.
Almost a meter of ice
The day before, to carry out this coordinated exercise, the first of its kind with their Martegal colleagues, the men of the high mountain gendarmerie platoon (PGHM) from Briançon fought for nearly three hours with a chainsaw, then with a barbell. mine, in order to drill three holes in the 80 centimeters of ice, and thus delimit on the lake an equilateral triangle of one meter on a side. All before transporting the 450 kg of diving equipment from the Martegal gendarmes thanks to the area’s snow groomer, made available by the resort.
“This lake is a kind of mille-feuille, a superposition of layers of ice with water, explains Denis Brun, rescuer at the PGHM. We set up a lifeline attached to a dead body, outside the lake, so that we could test the ice and be able to get there without danger. There was also a survey work to know the thickness of the ice. Had to drill with the ice screw. And beyond twenty centimeters, we know that we fear nothing. Beware, moreover, of those who would literally like to get off the beaten track, at the risk of finding themselves trapped in polar water.
A challenging dive
A black case in hand, Denis Brun cautiously scans the surface of the ice. The little machine emits a shrill sound, then another, and this in an increasingly short lapse of time. “There, he is very close! exclaims the rescuer. On the other side, a diver from the nautical brigade follows the ropes erected as a lifeline, without support or the possibility of perforating the ice which acts as the sky. Patiently, calmly, the gendarme makes his way through the bubbles of oxygen retained by this ice cap, resting on milky water, where visibility does not exceed two meters… and the temperature two degrees.
An exercise as physical as it is technical, even for these seasoned divers, who had to change directly in the snow. With altitude in particular, the decompression stops change, and fatigue is felt. “I’m out of breath, is surprised Lieutenant Sébastien Puccini, head of the nautical and river brigade of Martigues. We are at altitude, and they, the PGHM gendarmes, are used to it. We, a little less… I was smart earlier to go upstairs with my bottles. I was drained. You consume a lot of calories. Now I’m starting to get cold. And again, we did it with the sun! On your own, I think we could do research for thirty to forty minutes. But not more. »
“With this altitude, we lack oxygen, abounds Adrien, also a member of this brigade. That’s the hardest thing to deal with. And then usually, when we go out, we have the boat, or the shore. There, you have to walk in the snow and carry everything. A rare practical exercise that will lead to the writing of valuable sheets to train new divers in these perilous operations.