(CNN)It vanished January 27, 1968, but the wreckage of the French submarine Minerve has finally been found about 28 miles off the southern coast of France, near the port of Toulon.
Fifty-two crew members were on board when it went missing.
The search was made possible thanks to "recent technological advances in underwater exploration, including the use of new sonars and research drones," French Defense Minister Florence Parly said in a statement Monday.
The wreckage was discovered at a depth of nearly 1½ miles.
The French Alternative Energies and Atomic Energy Commission analyzed seismic measurements from the time when the Minerve disappeared to narrow the research area, and the navy's Hydrographic and Oceanographic Service provided scientific direction for that research.
The United States-based exploration company Ocean Infinity was then able to help identify the Minerve based on an initial sea-bottom mapping by L'Institut Français de Recherche pour l'Exploitation de la Mer.
"I sincerely hope that this discovery will help them to mourn, more than 50 years after this tragedy that has marked the French navy and all our fellow citizens," Parly said.
She has asked for a commemorative ceremony at sea for the families of the 52 sailors who died. The wreck will stay where it is, serving as the sailors' final resting place, the French navy said.