Deepest dive by a crewed vessel (solo)
Victor Vescovo
10,925 metre(s)
Not Applicable ()

Private equity investor, former naval officer and explorer Victor Vescovo (USA) descended solo into the"Eastern Pool" of the Challenger Deep in the Mariana Trench – Earth's lowest known point – in the deep-sea submersible Limiting Factor on 28 April 2019 and 1 May 2019. The maximum depth, averaged from pressure readings taken by a pair of calibrated CTD (conductivity/temperature/pressure) sensors installed on the submarine, was 10,925 m (35,843 ft), with a standard deviation of 4.1 m (13 ft 5 in). This was the fourth dive in Vescovo's "Five Deeps Expedition" in which he set out to become the first person to visit the deepest point of Earth's five oceans; he completed this mission on 24 August 2019 after successfully reaching the bottom of the Arctic Ocean's Molloy Deep. Vescovo returned to the Challenger Deep in June 2020 and conducted a series of six further dives in the Limiting Factor (none of them were solo, however), generating even more comprehensive data; by 26 June 2020, Vescovo had made the descent a record eight times. Independent analysis of the latest data by expert hydrographers has extended the depth of the Eastern Pool further still to 10,934 m (35,872 ft), with a deviation of +/- 3 m at 1-sigma or +/- 6 m at 2-sigma.

Of the four pressure readings gleaned from the two descents in 2019, the greatest depth recorded by one of the CTD sensors was 10,929 m (35,856 ft) on the first dive and the least was 10,920 m (35,826 ft) on the second dive. A third dive was conducted on 3 May 2019, piloted by the submersible’s builder, Patrick Lahey, and accompanied by a DNV-GL inspector from Germany, Jonathan Struwe. The average pressure readings indicated they reached a peak depth of 10,924 m (35,839 ft) on that dive.

All the dives were performed in the deep-sea submersible Limiting Factor, which was developed by Triton Submarines and whose commercial certification and diving depths were validated by international maritime authority DNV-GL.

Vescovo worked with a host of engineers, scientists and deep-sea diving specialists on the Five Deeps Challenge, including Captain Don Walsh (USA, retired US Navy), who along with Jacques Piccard (Switzerland) became the first people to reach the bottom of the Challenger Deep on 23 January 1960 in the Trieste bathyscaphe. James Cameron (Canada) made the first solo dive to the bottom of the Challenger Deep in 2012 in his Deepsea Challenger to a reported depth of 10,908 m (35,787 ft).

Details of the five dives of the Five Deeps Expedition are as follows:

- Atlantic Ocean: 19 Dec 2018: Puerto Rico Trench: 8,376 m (27,480 ft)

- Southern Ocean: 3 Feb 2019: South Sandwich Trench: 7,434 (24,390 ft)

- Indian Ocean: 5 Apr 2019: Java Trench: 7,192 m (23,596 ft)

- Pacific Ocean: 28 Apr 2019: Challenger Deep (deepest point on Earth): 10,925 m (35,843 ft) [since updated to 10,934 m (35,872 ft) based on new data]

- Arctic Ocean: 24 Aug 2019: Molloy Deep: 5,551 m (18,212 ft)

On the 2020 expedition to the Challenger Deep, several further records were set by passengers who accompanied Vescovo on his dives. These include the first person to visit space and the Challenger Deep and the first woman to reach the Challenger Deep (Dr Kathy Sullivan) and the first woman to reach the highest and lowest points on Earth (Vanessa O'Brien).

Vescovo has also achieved the Explorers' Grand Slam (Last Degree), which involves climbing the Seven Summits (the highest mountain on each continent) and reaching the North and South Poles.

The Challenger Deep is located in the South Pacific Ocean approximately 300 km (186 mi) southwest of Guam.