On the first of June, two men and a rabbit set sail from the port of Long Beach, bound for Hawaii, on a raft made of junk. Their cabin is the cockpit of a Cessna 310, white with a blue racing stripe, salvaged from the desert. It floats on a system of handmade pontoons -- 15,000 plastic bottles held together with recycled nets -- propelled by currents and wind. If it sounds dangerous and makeshift, that's the point. The pilots of Junk, as the vessel is called, want to get your attention. They are Dr. Marcus Eriksen, director of research...