ST. PETERSBURG, November 24. /TASS/. A sixth diesel submarine of project 636.3 (the Varshavyanka family) - The Kolpino - built for the Black Sea Fleet has entered service, a TASS correspondent reports.

The naval St. Andrew Flag was hoisted on board at the Admiralty Shipyards in St. Petersburg, where the whole family of submarines for the Black Sea Fleet has been built.

"Alongside the construction of multi-role missile-armed and multi-role submarines the Russian Navy’s command pays great attention to building a fleet of non-nuclear submarines… I am certain that this event will go down in the history of the Russian navy. Today we are delivering the lasts in a series of submarines for the Black Sea Fleet. This series will be far more effective in coping with its tasks in combination with surface ships and naval aircraft," the Russian Navy’s commander, Vladimir Korolyov, said at the ceremony.

He said the newly-built submarines were highly reliable and boasted effective weaponry. This year the keels of seven new submarines and surface ships has been laid, he recalled.

"The Admiralty Shipyards have done a great job to complete the Black Sea Fleet series of submarines. This is a good platform for starting the construction of another series of sub for the Pacific Fleet," Admiralty Shipyards CEO, Aleksandr Buzakov said at the ceremony.

The sixth Varshavyanka submarine was set afloat on May 31. Currently five project 636.3 submarines are on duty. The first two - The Novorossiysk and the Rostov-on-Don were handed over to the Navy in 2014. Another two - The Stary Oskol and The Krasnodar - followed in 2015. The fifth - The Veliki Novgorod entered duty in October 2016.

Project 636.3 submarines were developed at the central design bureau Rubin. They have a speed of 20 knots, endurance of 45 days, crew of more than 50, surface displacement of 2,000 tonnes and underwater displacement of about 4,000 tonnes.

The batch of six submarines for the Black Sea Fleet began to be built in 2010. The work on another such series meant for the Pacific Fleet will commence in 2017. The estimated completion date is 2021.

At the end of 2015 the Rostov-on-Don, while on a mission in the Mediterranean, launched cruise missiles Kalibr at targets of the terrorist group calling itself the Islamic State (outlawed in Russia) in Syria.