SEVASTOPOL, March 19. /TASS/. The Russian Black Sea Fleet’s submarine Stary Oskol armed with Kalibr cruise missiles has taken to the sea for joint drills with naval aviation and anti-submarine warfare ships, the Fleet’s press office reported on Tuesday.

"As part of its deployment to sea, the crew of the submarine Stary Oskol will practice various drills with naval aviation and anti-submarine warfare ships of the Black Sea Fleet, and will also sharpen the skills of placing the sub on the seabed," the statement says.

The submarine crew earlier held seaborne drills for the sub’s control and submergence to various depths, from the periscope to the operational depth, using different methods: both while adrift and on the move.

The Stary Oskol is the third Project 636.3 (Varshavyanka) diesel electric submarine that arrived for the Black Sea Fleet in 2015. Overall, six such subs have been built for Russia’s Black Sea Fleet.

Project 636.3 submarines have been designed by the Rubin Central Design Bureau. They develop a speed of up to 20 knots, have sea endurance of 45 days and a crew of over 50 men. The submarines of this class displace over 2,000 tonnes in their surface position and about 4,000 tonnes under the water. Varshavyanka-class subs are armed with Kalibr cruise missiles.

Project 636 submarines are considered to be the most noiseless among Russian conventional subs. They have been dubbed the ‘Black Hole’ for their unique quietness. They are also furnished with modern radar and communications systems, sonars and 533mm torpedoes.