Story highlights Cameron hits Challenger Deep, part of the Mariana Trench, a spokeswoman says

He's the first person to dive solo to that spot, the deepest in any of the world's oceans

Cameron is the director of blockbuster hits such as "Titanic" and "Avatar"

Oscar-winning director James Cameron has plunged to the deepest known point in the world's oceans, tweeting from his one-man submersible during the process.

The filmmaker reached Challenger Deep, which is part of the Mariana Trench in the western Pacific Ocean, near Guam, at 7:52 a.m. Monday (5:52 p.m. ET Sunday), according to Ellen Stanley, a spokeswoman for the National Geographic Society that is working with Cameron on the project.

"Just arrived at the ocean's deepest pt," Cameron wrote on Twitter. "Hitting bottom never felt so good."

At more than 10,900 meters (about 35,800 feet), the Mariana Trench is deeper than Mount Everest is tall. And it has had only two previous human visitors, as U.S. Navy Lt. Don Walsh and late Swiss explorer Jacques Piccard descended to that spot in 1960.

Cameron is the first person to make the dive solo, a distinction that also had been sought by billionaire businessman and adventurer Richard Branson and Patrick Lahey, an experienced submarine pilot.

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The man behind the blockbuster hits "Titanic" and "Avatar" went down in a high-tech vessel, the Deepsea Challenger, which he and a team of scientists and engineers constructed in Australia over the past eight years.

Outfitted with special cameras and robotic arms, Deepsea Challenger is able to dive vertically at speeds of 500 to 700 feet per minute and can withstand immense pressure -- up to 16,000 pounds per square inch.

Engineers and scientists joined Cameron's team during Sunday's deep sea endeavor. Earlier, he'd said he plans to spend six hours at the bottom of the trench collecting samples for research that will allow scientists on board and around the world to learn about the habitat and life forms at that depth.

"It's so exciting -- every second you see something cool or you've got something to do or you're photographing or you see some amazing fish," Cameron told CNN earlier this month.

Scientists hope that a fresh look at Challenger Deep will provide insight into many unfamiliar life forms in the depths of the ocean.

It is estimated that more than 750,000 marine species have not been formally described in scientific literature over the centuries, triple the number of those that have been. The figures exclude microbes, of which a 2010 marine life census estimates there are up to one billion kinds.

The nonprofit X-Prize Foundation has announced it will award a $10 million prize to the first person to reach the bottom of the Mariana Trench. Cameron told CNN he's not interested in competing for this prize, or any other, because his mission is purely about scientific research.

"You know, there's so much we don't know," Cameron said. "I'm hopeful that we'll be able to study the ocean before we destroy it."