By Ian Williams, NBC News correspondent

As last-minute supplies were brought on board the research ship, technicians tightened bolts on a mini-submarine sitting on the deck and tested its cameras. The ship's tannoy crackled to life inviting all scientists to a meeting in the library, and Bill Chadwick could barely conceal his excitement.

"Around half the species we've found are new to science, It's really a fantastic frontier," he told me.   We'd met Chadwick in Guam on board the RV Thompson, a research ship operated by University of Washington, at the start of an expedition he was leading to study a bubbling underwater volcano off the North Mariana islands in the Pacific.

His was one of the first expedition to the area's volcanic arch since it was designated a marine protected zone - a national monument - by President Bush, one of the last acts of his presidency.

Unique species of crabs, mussels, scrimps and worms have been found near the volcano's vents - and they are the ones we know about.

"These are special and unique things," Chadwick says. "They deserve protection."
Ninety-five thousand square miles of ocean around the North Marianas - an area the size of Oregon - is being given US federal protection - one of three vast areas of the Pacific named by President Bush, where commercial fishing and oil and gas exploration will be restricted.

It includes pristine reefs, which host some the largest densities of sharks in the Pacific.   And at its heart, the Mariana Trench, the deepest canyon on earth. Its barren bottom is almost seven miles beneath the surface, which means you would comfortably fit Mount Everest down there. It has barely been explored.

VIDEO: Working to preserve a world under water

"We can reach the moon, but we can't reach the bottom of the Mariana Trench. What kind of life is down there? What kind of scientific discoveries are yet to be found?" says Angelo Villagomez, of the Friends of the Monument, which led a vigorous campaign for a protected area.

The Trieste, a 2-man min-sub operated by the US Navy, did reach the bottom in 1960. Since then, the only vessel to come close, was an unmanned Japanese research sub in 1995. Next month, though, they'll be another US attempt, this one unmanned, in a mini-sub called the Nereus from Woods Hole Oceanographic Institution.

Scientists are heralding a new era in marine exploration.
For his part, Villagomez sees the establishment of Mariana trench National Monument as the ocean equivalent of the setting up of Yellowstone, the first park on land, in 1872.

"I would hope that other nations will look at what the US has done. It's set a new paradigm in marine conservation," he told me.

The Friends of the Monument are based on Saipan, the capital of the North Marianas, best known for one of the fiercest and most decisive battles of the Pacific War, which cost the lives of 30,000 Japanese and three thousand American troops.

 The wrecks of ships, aircraft, tanks and landing craft litter the coast here.
We caught up with Villagomez as he addressed student's at Saipan's Hopwood Junior High School, part of campaign that mobilized Saipan's tiny, 50,000-strong population behind the monument.

"How many of you wrote letters to President Bush?" he asked as a sea of hands were raised in the air.  From radio chat shows, to a petition drive, they spread the word that Saipan could gain enormously by being at the heart of such a pioneering act of conservation. Initially, local officials were lukewarm, seeing the proposed federally managed monument as a threat to their powers.

The conservationists had wanted more - some of the underwater volcanoes along the volcanic arch are outside the protected are, as are some of the shark habitats in a neighborhood well within the range of Chinese fishing boats, eager to feed the appetite for Shark fins, one of the biggest threats faced by these endangered predators.

"But it is a start," says Villagomez. "Down the road, I see the protection increasing, I see the borders expanding."  Challenges do lie ahead. It's still not clear how tough the new rules on fishing and exploration will be, and precisely how the monument will be managed and policed.

The Friends showed us Saipan's existing protected areas, which have succeeded in bringing back fish to the reef - and were we witnessed a remarkable underwater parade of protected giant Eagle Rays.

"We're seeing bigger fish, more fish, a greater density of fish," according to John Starmer from Saipan's Coastal resources management Office. "It's a great time to be marine biologist here."

But there were also signs of the perhaps inevitable conflict between conservation and livelihoods: fishing tackle twisted around delicate coral, the tell-tale signs of illegal fishing.

At present just two small boats police these areas, manned by officials of the local fish and wildlife service. The new, bigger area, will depend heavily on satellite imagery to plot the course of ships, looking for those lingering or zigzagging like fishing boats.

"We are going to need more muscle," says Alvin Fitial, a local conservation officer.
Before leaving Saipan, the NBC team was invited to a barbecue on the beach, where conservationists listened to Cinta Kaipat,  a former congresswoman and long-time social campaigner.

"Preserving the oceans, protecting the environment is so important - for conservation, but also for our very survival," she said.

There was enthusiastic applause as the sun dipped beyond  the horizon and the rusting turrets of tanks emerged from the receding ocean, now recognized for so much more than the wreckage of war.