Moscow: The Russian Navy launched a new diesel-electric submarine, a latest addition to its Black Sea Fleet, media reported on Friday.
The submarine was launched on Thursday in a ceremony held in St Petersburg, Xinhua reported.
A Navy official said that the new diesel-electric submarine Rostov-na-Donu, along with other vessels in the ongoing Project 636 series, represented modernisation of existing Russian submarine technology.
"The outside remains the same, but inside is completely different: a new torpedo defence system, new acoustic technology and new radio-electric equipment," the official said.
Rostov-na-Donu will join its Project 636 sub Novorossiysk for Black Sea duties which will include working together with surface forces and anti-submarine aircraft.
As well as covering the Black Sea, the new sub is also set to assist Russian naval activities in the neighbouring Mediterranean Sea.
Over the next few years, a total of six diesel-electric submarines would join the Black Sea Fleet under Project 636.
The vessels are designed to combine a high level of stealth with the ability to detect and attack enemy craft from a long range.
Project 636 is part of a broader development strategy for Russia`s Black Sea Fleet.
Russian Defence Minister Sergey Shoigu promised an investment of more than 86 billion rubles (about USD 2. 55 billion) in the Black Sea Fleet by the year 2020.