from..http://geology.com/press-release/deepest-part-of-the-ocean/

The Abyss: Deepest Part of the Oceans No Longer Hidden

A June, 2009 press release of the National Science Foundation.


World-Record Dive to 10,902 Meters


The Abyss is a dark, deep place, but it's no longer hidden. At least when Nereus is on the scene. Nereus is a new type of deep-sea robotic vehicle, called a hybrid remotely operated vehicle (HROV).

Nereus dove to 10,902 meters (6.8 miles) on May 31, 2009, in the Challenger Deep in the Mariana Trench in the western Pacific Ocean, reports a team of engineers and scientists aboard the research vessel Kilo Moana.

The dive makes Nereus the world's deepest-diving vehicle, and the first vehicle to explore the Mariana Trench since 1998.

"Much of the ocean's depths remain unexplored," said Julie Morris, director of the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the project. "Ocean scientists now have a unique tool to gather images, data and samples from everywhere in the oceans, rather than those parts shallower than 6,500 meters (4 miles). With its innovative technology, Nereus allows us to study and understand previously inaccessible ocean regions."