Paul-Henri Nargeolet, Known as ‘Mr. Titanic,’ Dies at 77

Paul-Henri Nargeolet, a renowned French maritime expert and submersible pilot, became a leading authority on the H.M.S. Titanic through 37 successful journeys to its wreckage. He was killed on his 38th attempt when the submersible craft in which he was traveling with four others imploded, the U.S. Coast Guard announced on Thursday. He was 77.

Perhaps no one was more intimate than Mr. Nargeolet with the wreck of the White Star liner that settled nearly 13,000 feet deep in the North Atlantic Ocean after sinking in 1912, killing more than 1,500 passengers and crew members. Often called “Mr. Titanic” for his knowledge of the ship’s wreckage and environs, he was the director of underwater research for RMS Titanic, the company that owns the salvage rights to the storied shipwreck, and the author of the book “In the Depths of the Titanic,” recently published by HarperCollins France.

His dozens of dives to the site included previous expeditions on the Titan, the vessel that disappeared on Sunday en route to the wreckage. On one such trip, in 2022, he helped with the discovery of an “extraordinarily biodiverse abyssal ecosystem on a previously unknown basalt formation near the Titanic,” according to the company that owned the Titan, OceanGate Expeditions.

James Cameron, the director of the popular movie “Titanic” and a friend of Mr. Nargeolet’s, described him as a “legendary submersible pilot.”

“For him to have died tragically in this way is almost impossible for me to process,” Mr. Cameron, who himself has made 33 dives to the famous wreck, said in an interview with ABC News on Thursday.

Few knew the wonders, as well as the risks, of such a dive more than Mr. Nargeolet. “If you are 11 meters or 11 kilometers down, if something bad happens, the result is the same,” he said in a 2019 interview with The Irish Examiner. “When you’re in very deep water, you’re dead before you realize that something is wrong, so it’s just not a problem.”

Mr. Nargeolet was born on March 2, 1946, in Chamonix, France, in the French Alps. He moved to Paris after living in Morocco for 13 years.

He heard the call of the sea at an early age as an amateur diver, and in 1964 joined the French Navy. He served as submarine pilot, mine-clearing diver and a deep-sea diver.

After 22 years of service, he went to work for the French maritime research institute Ifremer, where he oversaw its deep-sea exploration crafts during early expeditions to the site of the Titanic. He made his first journey to the site in 1987.

During that 100-minute plunge, the crew of three traveling in a submersible called the Nautile chatted incessantly until they finally caught a glimpse of the liner’s bow in the searchlights. “For the next 10 minutes there wasn’t a sound in the submarine,” he said in an interview last year with HarperCollins France.

His survivors include his wife, Anne Sarraz-Bournet; two daughters, Chloe and Sidonie; a son, Jules; a stepson, John Nathaniel Paschall; and a grandson. His wife Michele Marsh, an Emmy Award-winning newscaster in New York, died in 2017.

As a director for the RMS Titanic company, which salvaged more than 5,500 artifacts from the wreckage and according to the company’s website mounted exhibitions viewed by more than 35 million people, Mr. Nargeolet experienced gratitude for his role in preserving what many consider a symbol of the early 20th century optimism about technological progress, as well as scorn from some who consider it the equivalent of grave robbing.

“These expeditions have cost $50 million,” he told The Irish Examiner. “Of course, the company wants some return.”

He emphasized the benefits to science and history of preserving the remnants of a massive hulk of steel and iron that serves not only as a teeming habitat for rare species — “an oasis in a huge desert,” as he put it in an interview with Le Monde last year — but also as one of the great artifacts of a lost age that microorganisms are slowly turning into stalactites of rust.

“One morning, a survivor reproached me for recovering objects, her father having died in the catastrophe,” Mr. Nargeolet said in an interview last year with the French newspaper Le Monde, “and in the afternoon, another congratulated me and asked me to bring back the pearl necklace that her mother had left on her night stand!”