It was the voyage to break the record for the world's deepest ocean dive.
Details of his trip were released on Monday.
"Then in 2012, James Cameron made a solo dive there".
At the deepest point on the planet, Vescovo found what looked like plastic.
Deep in the middle of the Pacific Ocean, Vescovo dove 35,853 feet beneath the waves, breaking previous records by about 36 feet. "I think it is a wonderful part of human nature that makes us want to push ourselves to the limits, which has helped propel us as a species to where we are now".
View from "Limiting Factor" submarine during a Mariana Trench dive.
In the May/June issue of Hydro International we'll publish an article about the Five Deeps Expedition.
As well as the Mariana Trench in the Pacific, in the last six months dives have also taken place in the Puerto Rico Trench in the Atlantic Ocean (8,376m), the South Sandwich Trench in the Southern Ocean (7,433m) and the Java Trench in Indian Ocean (7,192m).
It was the third time humans dived to the deepest point in the ocean, known as Challenger Deep.
The ocean depths represent some of the least explored and remote places on the planet. Previously, the deepest dive totaled over 10,912 metres and was carried out by U.S. Navy lieutenant Don Walsh and Swish engineer Jacques Piccard in 1960.
He is attempting to become the first person to travel to the deepest part of the Earth's five oceans and needs only one more dive to complete the Five Deeps: the Molloy Deep in the Arctic Ocean at 18,599 feet.
Tests by Newcastle University researchers found that sea creatures living in the deepest reaches of the sea had fragments of plastic in their stomachs and muscles.
The creative director of Atlantic Productions, Anthony Geffen, explained it is the hardest thing he has ever filmed, due to the near-freezing temperatures and pitch black the sub operates in. By 2025, they estimate the annual input will be about twice that. The group is using a submersible called Limiting Factor to complete its challenge.
"It is nearly indescribable how excited all of us are about achieving what we just did", said Vescovo in a statement emailed to IFLScience.
"That is my honest hope - to sell the system to an institute, government, or individual, that can use the whole diving system to advance marine science for decades to come". It is built to dive for 16 hours at a time-but also has emergency air supplies for a further 96 hours. "That is the story of our species, and I am just so happy that even if in a small way, I have been able to contribute to forward progress".