Since 1979 he has been the director of the Russian (former Soviet) Deepwater Submersibles Laboratory.
Sagalevich took part in the construction of Pisces VIII, Pisces IX and MIR Deep Submergence Vehicles (DSV) and completed more than 300 submersions as the chief pilot of DSVs.
Sagalevich holds the world record for the deepest fresh water dive, at 1,637 meters (5,371 ft) (in Lake Baikal aboard a Pisces in 1990).
[3] On 2 August 2007 Sagalevich was the pilot of MIR-1 DSV, which reached the seabed at the North Pole during the Arktika 2007 expedition.
On 10 January 2008 Sagalevich was awarded the title Hero of the Russian Federation for "courage and heroism shown in extreme conditions and successful completion of High-Latitude Arctic Deep-Water Expedition.