In these icy oceans, falling overboard is a death sentence. Even so, humpback whales, killer whales, seals and a world of sea life roam the waters off Antarctica's shores. To understand and conserve these fragile ecosystems, scientists must brave the perils and study them. And if the science is to survive, then the US Coast Guard ice cutter Polar Star has to chop a channel through thick ice for a supply ship to traverse before time runs out.