In the morning, when we arrive on foot from Dumont d’Urville, the French scientific base on the Adélie Coast of East Antarctica, we have to break up a thin layer of ice that has formed over the hole we drilled the day before. The hole goes right through the 10-foot-thick ice floe. It’s just wide enough for a man, and below it lies the sea. We’ve never tried to dive through such a small opening. I go first.
Pushing and pulling with hands, knees, heels, and the tips of my swim fins, I shimmy through the hole. As I plunge at last into the icy water, I look back—to a sickening sight. The hole has already begun to close behind me.
The bottom surface of the sea ice is a thick slurry of floating ice crystals, and my descent has set them in motion. They’re converging on the hole as if it were an upside-down drain. By the time I thrust one arm into the icy mush, it’s three feet thick. Grabbing the safety rope, I pull myself up inch by inch, but my shoulders get stuck. Suddenly I’m stunned by a sharp blow to the head: Cédric Gentil, one of my dive buddies, is trying to dig me out, and his shovel has struck my skull. Finally a hand grabs mine and hauls me into the air. Today’s dive is over—but it’s only one of 32.