"Two devices are in the Sochi airport, the unloading is in the process, after that they will at once head to the area of the search operation. They will start operating today," Davydova told RIA Novosti.
The apparatuses are capable of working underwater for up to eight hours on the depth of 328-984 feet. They will be operated by the specialists of the RGS Underwater Research Centre. Experienced RGS divers will also work with the submersibles.
Among the main causes for the plane crash technical malfunction or pilot error have been suggested earlier.
According to the Russian Defense Ministry, 11 bodies have been recovered so far.