LESS ICE ACCELERATES global warming, but it also brings opportunity. The sea around the Healy is clear of ships at the moment, but beyond the horizon, every nation with Arctic seabed—the U.S., Canada, Russia, Denmark, Iceland, and Norway—is racing to secure undersea territory. According to some reports, an estimated 25 percent of all undiscovered oil and gas reserves are believed to lie under the Arctic, and with vast expanses of the region suddenly accessible, a massive land grab is afoot. Under the United Nations' Law of the Sea Treaty, any ocean nation can claim the exclusive right to the seabed up to 402 miles offshore if it can prove that the land is an extension of its continental shelf. Last winter, Russia made headlines by dropping a titanium flag at the North Pole. They've claimed an area as big as Spain and France combined. "The Arctic is ours," Russian legislator Arthur Chilingarov said. Norway has filed for a chunk of territory off its coast. Denmark has already spent a quarter of a billion dollars in support of its Arctic claims off Greenland. "This will be the greatest distribution of lands on earth possibly ever to occur," says Paul Kelly, a member of the U.S. Commission on Ocean Policy.

Despite currently cordial relations between Arctic countries, some experts worry that fighting may erupt if the process breaks down. Certainly, world leaders have started talking tough. According to a 2008 Coast Guard report, the Russians have "resumed strategic bomber flights over the Arctic for the first time since the Cold War." In June, right after the Arctic countries agreed to tone down their combative rhetoric, Lieutenant General Vladimir Shamanov, head of Russia's combat-training directorate, announced that his country would expand military activities in the North. Canada's prime minister, Stephen Harper, has said, "Use the Arctic or lose it," and has promised to increase the country's Arctic military presence.

As the Healy cruises off the Alaska coast, the midnight sun glows down on another security headache to our east. It's the Northwest Passage, the fabled shortcut between Europe and Asia. Though the route has been impassable because of ice for centuries, some experts predict that in as little as four years it may be completely ice-free during the summer. Canada claims the passage as national waters, but the U.S. wants it open for use by all. Even as we sail, the Canadians are setting up a new laser-imaging device to detect rogue ships slipping into the passage. They began interdiction exercises in 2006; during one maneuver, they fired a 57-millimeter cannon over the bow of a mock American ship trying to sail through.

"A quarter of the world's shipping may go through the Northwest Passage within 15 years," says Scott Borgerson, Arctic expert at the Council on Foreign Relations. A single Chinese container ship, after all, could save millions of dollars on fuel and tolls traveling to New York via the passage instead of the Panama Canal. Borgerson predicts that Alaska's Arctic coast may come to look like offshore Louisiana, illuminated by thousands of oil-platform lights, and an Alaska port like Dutch Harbor may become a global hub for shipping, as busy as Singapore.

If that sounds far-fetched, consider that in 2007 more than 200 tourist ships circled Greenland, up from 27 in 2004. Last year, three German cruise ships sailed through the Northwest Passage. One showed up at Barrow, the Healy's launch point. "We had no idea they were coming," said Coast Guard rear admiral Gene Brooks, head of Arctic operations. Suddenly hundreds of tourists were wandering around, asking, "Vere are zee polar bears?"