A mini-submarine and a remote-controlled robot that explored the undersea wreckage of the Titanic are being sent to help find the flight recorders of the lost Air France Airbus.
France's marine research institute Ifremer said the ship Pourquoi Pas? (Why Not?) left the Azores on Tuesday and could take up to 10 days to reach the waters off the north-east coast of Brazil where military aircraft are searching for the remains of the plane.
On board is the Nautile submarine, capable of descending to 19,600 feet below sea level and the robot, known as Victor 6000.
Search teams have a month to locate the plane's black boxes - cockpit voice and flight data recorders - before they stop emitting signals. They could be scattered nearly anywhere across a vast undersea mountain range below the surface of the Atlantic Ocean.
The Nautile made multiple dives to the Titanic in 1987, 1993, 1994, 1996 and 1998 to explore the wreckage.
However the head of France's accident investigation agency, Paul-Louis Arslanian, has said he was "not optimistic" that officials would ever recover the black boxes from the plane.