SEVASTOPOL, June 28. /TASS/. The Black Sea Fleet’s oldest submarine Alrosa has deployed to the sea for the first time over eight years for shipbuilders’ sea trials after its repairs and upgrade, the Fleet’s 13th Ship Repair Plant told TASS on Tuesday.

A source in Sevastopol defense circles earlier said that the submarine had become the carrier of Kalibr-PL cruise missiles after its upgrade.

"The submarine has deployed [to the sea from the Sevastopol Bay]. For the first time over eight years, it will be tested in various modes of operation and must prove its ability to operate according to its designation," the Ship Repair Plant said.

The Alrosa was built at the Krasnoye Sormovo Shipyard in the city of Gorky (now Nizhny Novgorod) shortly before the break-up of the Soviet Union and belonged to the experimental Project 877. As its specific feature, it was driven by a waterjet engine instead of propeller propulsion, which ensured its maximal stealth. Owing to this, submarines with waterjet engines are dubbed ‘black holes’ abroad. Soon after the break-up of the Soviet Union, the Alrosa remained Russia’s sole combat-fit submarine in the Black Sea.

It was reported in early May that the submarine’s repairs were over and the Alrosa had acquired new combat and technical capabilities that "put the Alrosa on a par with six subs that had arrived for the Black Sea Fleet in recent years".