SEVASTOPOL, May 19. /TASS/. The Black Sea Fleet ships and submarines searched for a notional enemy’s subs during drills, the Fleet’s press office reported on Tuesday.

"The crews of the diesel-electric submarines Rostov-on-Don and Kolpino of the Black Sea Fleet deployed to the sea for joint drills to search for and detect a notional enemy’s submarine. Under the combat training scenario, one of the submarines simulated an enemy sub while the crew of the second vessel searched for it," the press office said in a statement.

The crews of the submarines alternated their roles, first hunting for the enemy sub and then dodging the hunt, the statement says.

The submarines also practiced preparing the subs for their emergency deployment to the designated areas at Black Sea naval ranges, according to the statement.

The drills for searching for and tracking a notional enemy’s submarine simulated by the sub Kolpino also involved the crews of the small anti-submarine warfare ships Muromets and Yeisk. They carried out a set of preparatory exercises for employing torpedo weapons and held firings of practice torpedoes. The ships’ crews complied with the required time limits for employing torpedo weapons, the press office said.

The Admiralty Shipyard in St. Petersburg has built a series of six Project 636.3 diesel-electric submarines for the Black Sea Fleet. The three of them, the Veliky Novgorod, the Kolpino and the Rostov-on-Don, numerously delivered strikes with Kalibr-PL cruise missiles against terrorist targets in Syria.

Project 636.3 submarines are referred to the third generation of diesel-electric subs. These submarines are considered among the world’s most noiseless vessels. They develop a speed of up to 20 knots, can dive to a depth of about 300 meters and their sea endurance is 45 days. The sub has a crew of 52 men and displaces about 4,000 tonnes.

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.