It happened on August 3, 1997, a lovely day, at least in the beginning: Sunny. Little wind. Water the color of sapphires. Moore and the crew of Alguita, his 50-foot aluminum-hulled catamaran, sliced through the sea.
Returning to Southern California from Hawaii after a sailing race, Moore had altered Alguita's course, veering slightly north. He had the time and the curiosity to try a new route, one that would lead the vessel through the eastern corner of a 10-million-square-mile oval known as the North Pacific subtropical gyre. This was an odd stretch of ocean, a place most boats purposely avoided. For one thing, it was becalmed. "The doldrums," sailors called it, and they steered clear. So did the ocean's top predators: the tuna, sharks, and other large fish that required livelier waters, flush with prey. The gyre was more like a desert--a slow, deep, clockwise-swirling vortex of air and water caused by a mountain of high-pressure air that lingered above it.
The area's reputation didn't deter Moore. He had grown up in Long Beach, 40 miles south of L.A., with the Pacific literally in his front yard, and he possessed an impressive aquatic résumé: deckhand, able seaman, sailor, scuba diver, surfer, and finally captain. Moore had spent countless hours in the ocean, fascinated by its vast trove of secrets and terrors. He'd seen a lot of things out there, things that were glorious and grand; things that were ferocious and humbling. But he had never seen anything nearly as chilling as what lay ahead of him in the gyre.
It began with a line of plastic bags ghosting the surface, followed by an ugly tangle of junk: nets and ropes and bottles, motor-oil jugs and cracked bath toys, a mangled tarp. Tires. A traffic cone. Moore could not...