[7] Nargeolet began his career in the French Navy, where he served as an officer specialising in mine clearance, diving, and deep underwater intervention[3]: 1  from 1964 to 1986.

[10] In 1986, the French Research Institute for the Exploitation of the Sea (IFREMER) contacted Nargeolet about diving to the wreck of the Titanic; he heartily agreed to go.

[3]: 2 Beginning in 1994, Nargeolet was director of Michigan State University's Center for Maritime & Underwater Resource Management (CMURM).

[3][6] In 2010, he was part of a mission to 3D map the wreck site and determine levels of deterioration using ROVs and autonomous underwater robots.

[13] On 22 June, after the discovery of a debris field approximately 490 metres (1,600 ft) from the bow of the Titanic,[14] OceanGate said it believed Nargeolet and the four others aboard "have sadly been lost.

"[15] A United States Coast Guard press conference later confirmed that the debris was consistent with a catastrophic loss of the pressure hull, resulting in the implosion of the submersible vehicle.

[14] Nargeolet had two daughters, Chloé and Sidonie; a son, Julien; a stepson, John Nathaniel Paschall; and four grandsons.

[16][17][18] Later, as a result of his Titanic work, Nargeolet re-established contact with a childhood friend, Anne Sarraz-Bournet, who became his second wife.