Bathyscaphe Trieste
On 23 January 1960, she reached the ocean floor in the Challenger Deep (the deepest southern part of the Mariana Trench), carrying Jacques Piccard and Don Walsh. This was the first time a vessel, manned or unmanned, had reached the deepest known point of the Earth's oceans. The onboard systems indicated a depth of , although this was revised later to ; fairly recently, more accurate measurements have found Challenger Deep to be between and deep.
Submersible
James Cameron made a record-setting, manned submersible dive to the bottom of Challenger Deep, the deepest known point of the Mariana Trench on March 26, 2012. Cameron's submersible was named Deepsea Challenger and reached a depth of .