The Main Directorate of Deep-Sea Research (Russian: Главное управление глубоководных исследований, transcribed as Glavnoye upravlenie glubokovodnikh issledovanii or GUGI), is a Russian agency belonging to the Armed Forces of the Russian Federation. It is one of the most secret parts of the navy.[1] Its objective is to operate submarines that are able to dive deep into the sea, in order to gather intelligence or to work with installations on the seabed including sabotage.[2][3][4] Its original target was the Western surveillance systems of submarines from the Soviet Union[5] and it is able to eavesdrop and sever the fiber optic cables crossing the seas.[6][7] It also tests emergency equipment and does medical research on the physiology of diving.
The year of creation of the directorate is uncertain. 1963 (as military unit 90802), 1965,[8] and 1976 have been mentioned.[2]
The directorate is directly subordinate to the Ministry of Defense.[9][5] It is located separated from the normal navy bases, with its headquarters in Saint Petersburg and a naval base in Olenya Bay on the Kola Peninsula.[2]
GUGI has submarines that can reach depths of 6000 meters. They are equipped with tools, cameras and lighting in order to carry out operations there.[5] It has more than 50 ships, submarines and floating dry docks, which hide submarines from satellites.[4]