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.
Bottlenose dolphin
The deepest dive ever recorded for a bottlenose dolphin was 300 meters (990 feet). This was accomplished by Tuffy, a dolphin trained by the US Navy.
Nellie, the longest-lived Atlantic bottlenose dolphin in human care, died at age 61 on April 30, 2014. Nellie was born on Feb, 27, 1953 at Marineland.