Photo:JOEL SAGET/AFP via Getty Images

Paul-Henri Nargeolet

JOEL SAGET/AFP via Getty Images

French explorer Paul-Henry Nargeolet,one of the five people reportedly aboardthemissingTitansubmersible, was well aware of the dangers of deep-sea diving.

“If you are 11m or 11km down, if something bad happens, the result is the same,”he told theIrish Examinerin 2019. “When you’re in very deep water, you’re dead before you realize that something is happening, so it’s just not a problem.”

The former Navy captain, 77, is known as “Mr. Titanic” for his expertise and has been on over 35 dives to theTitanicwreck site, including the latest,according toThe New York Times. He is the director of underwater research for RMS Titanic Inc., which is responsible for salvage efforts of artifacts from the ship site.

According to Bloomberg, Nargeolet also shared another risk when voyaging to the ocean’s floor, where theTitanicrests: He once told the Titanic Channel that the cold temperatures would be one of the greatest dangers if explorers became stuck at the wreckage site.

TheTitanlaunched Sunday before communication was lost between the submersible and the Canadian expedition vesselPolar Prince“approximately 1 hour and 45 minutes” into the dive, U.S. Coast Guard Captain Jamie Frederick said at a press conference on Tuesday.

Alamy Stock Photo

The Oceangate submersible Titan

As the U.S. Coast Guard and Canadian Coast Guard continue their search and rescue mission for the vessel — which, if intact, could have about 40 hours of oxygen left, officials said Tuesday — loved ones fear for Nargeolet as well as the four other passengers.

Pakistani businessman Shahzada Dawood and his son Suleman Dawood are on board, their family and King Charles' Prince’s Trust International confirmed to PEOPLE on Tuesday.

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On Sunday, Nargeolet’s companywrote on Twitterthat it sent “heartfelt support” to the search and rescue effort.

“We send our thoughts and prayers for the safe return of all on board,” officers with the RMS Titanic Inc. wrote.

source: people.com