James Cameron Challenges Victor Vescovo's 'Record Breaking' Trip to Deepest Part of Ocean: 'It's Flat Down There, Impossible to Dive Deeper'

James Cameron has raised questions about Victor Vescovo's recent claims to have broken the record for the deepest ocean dive, saying the Dallas businessman cannot have descended further as there was no deeper point to reach.

The 65-year-old Hollywood director became the first to perform a solo dive to the bottom of the Mariana Trench in 2012, as part of the Deepsea Challenge. He spent over two-and-a-half hours descending into the trench, in the Pacific Ocean, eventually reaching the seafloor—at a depth of 35,787 feet—on March 26. This was the deepest manned dive ever performed.

But in May, Vescovo, 53, announced he had gone below Cameron's record, claiming to have reached a depth of 35,853 feet in the Mariana Trench's Challenger Deep—the deepest known point on Earth. This record, which made headlines around the globe, is now being contested.

"I put my hand up when I saw it becoming a matter of public fact without discussion in the media or science community," he told Newsweek in an email. "But what Mr Vescovo's group reported and what I witnessed in 2012, are two different things. He says he found a deeper hole in the bottom of the ocean. I say it's flat down there, impossible to dive deeper."

Before his dive, Vescovo and Cameron had been in contact—the director had offered him help and advice, and many of the Deepsea Challenger team that worked with Cameron were also involved in Vescovo's project: "He was very generous with his time, explaining where he went on his dive, helped me obtain maps of the dive area," Vescovo said at the time. "He very much thought we should go visit it for the benefit of science, so we did. I am extremely grateful for his expedition showing us technically what worked well and what needed enhancement, and helping us push deep ocean exploration forward in a very collaborative and supportive manner."

Cameron said his motivation for going to the Mariana Trench was not to break records, but to build a submersible and see some of the deepest parts of the ocean. Records, he said, were not at the forefront of his mind, adding he "never claimed to have gone deepest." Instead, Cameron says, he felt he shared the record with Don Walsh and Jacques Picard, who dove into the Challenger Deep in 1960.

During his trip to the Challenger Deep, Cameron spent about three hours exploring the region, collecting samples and videos, while also mapping the area. "What I observed down there was a flat plain that didn't deviate more than a meter up or down over almost two kilometers of horizontal searching. My colleagues at Woods Hole Oceanographic Institution (WHOI) saw the same thing in 2009 when they dove there with the Nereus remotely operated vehicle. In fact right after I landed I saw the track in the sediment left by Nereus, so I was right where they explored.

"They observed a plain that was flat within a meter or so for several kilometers east and west, as well as north and south. So our conclusion back then, and today, is that it's not really possible to go deeper."

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James Cameron at the premiere of Alita: Battle Angel in January 2019. Cameron dove to the deepest part of the ocean in the Mariana Trench in 2012. Dave J Hogan/Getty Images

Cameron and researchers with the WHOI say the difference between the depth recorded by Deepsea Challenger and Vescovo's submersible relates to the technology used. Measuring ocean depth is not as straightforward as measuring distance on land. "There's no such thing as underwater GPS. You can use sound waves—sonar—but at extreme depth sonar scans have an error margin of plus or minus 20 meters (65 feet), mostly due to the sound pulses penetrating the bottom and creating a false reading. Mr Vescovo may have put too much faith in his state of the art multibeam sonar."

Many things can affect measurements taken, including changes to temperature and the salinity of the water. "Just as you can't step in the same river twice, you can't measure the same water column twice," Cameron said. "This creates error margins, for the best instruments of plus or minus 10 meters (32 feet)."

Cameron says that he believes Vescovo took the best measurements with the equipment he could—but coming to the surface and claiming he broke the record for deepest dive was inaccurate: "He may have done no more than reveal inaccuracies in the readings we took in 2012."

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The NOAA's Deep Discoverer in the Mariana Trench in 2016. Research into the deepest parts of the ocean is hugely underfunded, Cameron says. NOAA Office of Ocean Exploration and Research, 2016 Deepwater Exploration of the Marianas

The focus on breaking records, Cameron and researchers at the WHOI believe, is detracting from deep sea research. Over 80 percent of the ocean is "unmapped, unobserved, and unexplored," the NOAA says.

And studying the deepest parts of the ocean is an area of science that is underfunded—earlier this year it was announced funding for NOAA's Oceanic and Atmospheric Research would be cut by 41 percent for the 2020 fiscal year.

Cameron said Vescovo's dive to the Mariana Trench was hugely important for science. He collected many more samples, discovered new species and, hopefully, helped pique public interest in the deep ocean trenches—and the need for more research into this remote region.

Vescovo has invited Cameron to look at the data from both dives at a workshop with experts in depth measurements, the Avatar director said. This, he said, is in the "same vein of collaboration and the pursuit of scientific truth...He's also invited me to dive with him in his sub, the Limiting Factor, when he returns to Challenger Deep and other hadal sites, hopefully next year. Our curiosity unites us in a common cause."