August 31, 2006—For divers in Antarctica, it's no day at the beach. Adventurers need to ditch their swimsuits for long underwear, wool socks, and fleece gloves—and that's just for under their wet suits. But the extreme cold is not without its rewards: Antarctica's waters teem with life unlike anywhere else on Earth.

Go beneath the surface and witness some of the world's oddest creatures: fish with "antifreeze" in their blood, giant-legged spiders, thousand-year-old sponges—perhaps even a new species.