Triangle 2009 Movie Dual Audio 1

On 5 June 2009, the French nuclear submarine Émeraude was dispatched to the crash zone, arriving in the area on the 10th. Its mission was to assist in the search for the missing flight recorders or "black boxes" that might be located at great depth.[152] The submarine would use its sonar to listen for the ultrasonic signal emitted by the black boxes' "pingers",[153] covering 13 sq mi (34 km2; 9.8 sq nmi) per day. The Émeraude was to work with the mini-sub Nautile, which can descend to the ocean floor. The French submarines would be aided by two U.S. underwater audio devices capable of picking up signals at a depth of 20,000 ft (6,100 m).[154] 2b1af7f3a8