Last summer, Rooney was one of 20 people who spent 28 days aboard the research ship Hi'ialakai to study the area, which will take decades to map. "When I'm towing a camera sled across the seafloor, I'm looking at a seafloor that probably nobody has ever looked at," he says.

In addition to housing the predators, coral, and sea turtles, the Northwestern Hawaiian Islands also hold important pieces­ of world history. Historical records make it clear that there may be as many as 60 shipwrecks in the area, along with at least 67 planes - many of them Japanese and American fighters from World War II. "The way the Northwestern Hawaiian Islands stretch themselves across the ocean and the fact that they're [packed with] low reefs and coral atolls with no navigational aids - they're incredibly treacherous. They're like a net, a comb lying across the Pacific. These places are shipwreck magnets," says Hans van ­Tilburg, PhD, maritime heritage coordinator for the NOAA National Marine Sanctuaries Program. "You wouldn't even know it on a dark night. You would be sailing way out in the middle of the Pacific and would run into the reefs all of a sudden. There's no land, no mountains to see ahead of time. We know that there's a lot more stuff out there than even the records reflect."

While the islands' remote location has offered some protection against fishing, it has also helped save the shipwrecks from looters - a problem in other parts of the world. Van Tilburg made one of his favorite finds so far in 2003 at Kure Atoll, the very end of the 1,300-mile island chain. There, he and his team discovered the remains of the USS Saginaw, a Civil War-era ship that crashed into a reef in 1870. After picking up divers who were attempting to clear a channel into Midway Atoll, the Saginaw was sailing home when the captain decided to see if there were any castaways stuck on Kure Atoll - "a pretty responsible thing for the captain to do," says Van Tilburg.

It was that act of kindness that spelled doom for the Saginaw. Ninety-eight men were stranded on the island. Five boarded a small rescue boat to get help, but just one of the five survived. He relayed word of the wreck, and soon after, all the other men were rescued.

Over the past 137 years, the remains of the Saginaw have been pushed into the atoll. The dive, says Van Tilburg, is intense. “There are these huge rifled cannons from the Civil War and all these deck fittings for this steamer, which was built in 1858. We’re on the exact same spot [that] 98 guys abandoned ship onto that coral reef … and stood there shivering until the sun came up. That’s the location where we’re diving. There’s a sense of connection to a historic event. It’s very strong.”
Fackler, Rooney, and Van Tilburg all plan to spend more time exploring the islands. “They’re such a blank slate; it’s crazy,” says Rooney.