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.
Cheyenne (catamaran)
In 2009 Cheyenne was purchased by Chris Welsh from the estate of Steve Fossett. Plans are to launch a deep sea submarine to carry passengers to extreme ocean depths. The deep sea adventure will be supported by Cheyenne, and will use the HOT DeepFlight Challenger sub to plumb the depths of the worlds oceans to full depth. Both of these were owned by Steve Fossett, who had modified the racing catamaran to become the mothership to his oceanic dive record attempt. The submarine seats one person, and is currently the only manned submersible capable of reaching the deepest part of the oceans.The former records have all been broken.