Don Walsh (left), deepest diver in 1960, congratulates Victor Vescovo. (Picture: Reeve Jolliffe)
The fourth of Victor Vescovo’s Five Deeps Expedition submersible missions has resulted in the US explorer becoming the deepest diver in history.
Piloting his submersible Limiting Factor, built by Triton Submarines, he reached a maximum depth of 10,928m at Challenger Deep in the Pacific Ocean’s Mariana Trench. His solo dive beat by just 16m the record set almost 60 years ago by the Trieste bathyscape, piloted by Don Walsh and Jacques Piccard in 1960.
Walsh was aboard the mothership DSSV Pressure Drop to witness what was not one but a series of deep dives. “This was a demonstration of system reliability and operational efficiency never seen before in exploration of the oceans’ deepest places,” he commented afterwards.
James Cameron made the first solo dive to the Mariana Trench seabed in Deepsea Challenger in 2012, though he was a few metres short of Trieste’s maximum depth. The Trieste and Deepsea Challenger missions were both restricted to single attempts, but the Limiting Factor made five dives between 28 April and 5 May, including one in the Sirena Deep.
The deepest dive was in fact achieved at the first attempt, one of two solo dives by Vescovo. It involved a four-hour exploration of a relatively flat part of Challenger Deep known as the Eastern Pool, and was the longest period ever spent at the bottom of the ocean by an individual.
His second solo dive took place on 1 May, while the other three dives included both a pilot and a scientific specialist.
Also read: What on Earth is next for Vescovo?
The third dive turned out to be the deepest marine-salvage operation ever attempted. A scientific lander had become stuck on the seabed during the previous dive, and was successfully freed and recovered.
The scientific team identified at least three new species of marine animal during the dives, including a type of long-legged crustacean. Less welcome was the recording of marine pollution in one of the world’s most inaccessible places, in the form of sweet wrappers and a plastic bag.
The descents and ascents averaged 3.5 hours each way, with missions lasting on average from 11-12 hours, including submersible launch and recovery times. The Limiting Factor is designed to support two people for up to four days.
Another new record was set when pilot John Ramsay, the submersible’s principal structural designer, became the first British citizen to descend to the bottom of Challenger Deep.
The Five Deeps Expedition aims to reach the deepest known points in all five oceans. The Atlantic, Southern, Indian and now Pacific Oceans have been covered by Vescovo and his team over the past four months, with only the Arctic now remaining. Atlantic Productions is filming a five-part Discovery Channel documentary on the mission, due to be broadcast later this year.
“It is almost indescribable how excited all of us are about achieving what we just did,” said Vescovo, after arriving in Guam following the Mariana Trench dives. “We feel like we have just created, validated and opened a powerful door to discover and visit any place, any time, in the ocean – which is 90% unexplored.”
With his dives Vescovo, who is 53 and a private equity investor, also became the first person to have both reached the summit of Mt Everest and been to the ocean’s deepest-known point, as well as having skied to both the North and South Poles – his version of visiting “the four corners of the Earth”.
He has also climbed the highest peak on every continent – “the Seven Summits” – and hopes with the final dive of the Five Deeps Expedition at Molloy Deep in late August to complete his set of ocean descents in the Arctic.
Before that, the next planned dive is at Horizon Deep in the South Pacific’s Tonga Trench. It is thought possible that this could prove to be even deeper than the Mariana Trench.