National Geographic : 2001 Dec
n opening in an old iceberg grounded off Cape Hallett beckoned like an endless grotto. Jill and Paul Heinerth, both veteran explora tion research divers, swam into it with Wes Skiles following. All wore advanced rebreathing gear, which recycles their exhalations, add ing life-sustaining oxygen. Skiles: "This was definitely pio neer diving. We were staying longer at these depths than people ever thought about in this kind of water. We were film ing and science sam pling successfully because of the tech nology. That said, I hope I never have to make another series of dives that are so high risk." A thou sand feet in and 130 feet down they came upon a garden of life. An alien-looking iso pod (below left) about five inches long swam by. The bot tom was rich with ABYSSOCUCUMISTURQUETI feather duster worms (below middle) and sea cucumbers (below). While much of the seafloor had been scoured clean of life by icebergs bulldozing along the bottom, here the grounded berg had provided shelter. Their work done, the three divers attempt ed to swim out, but they were stopped by an adverse current. "Jill and Paul could make some forward progress, but I was getting swept back into the cave," Skiles recalls. Swimming shoulder to shoulder, they at last found a depth where the cur rent eased. Making slow progress, they reached open water, overdue and to-the bone cold-but safe. Four hours later the iceberg exploded.