The Defense Ministry plans to complete sea trials of a new diesel Lada-class submarine this year, a military official said on Wednesday.
"The Navy will complete trials of the Lada-class submarine equipped with new sonar systems in 2009," said Maj. Gen. Alexander Shevchenko, in charge of the Armed Forces' armaments maintenance and support.
A deputy head of the Navy General Staff said in March that the first Lada-class would enter service with the Russian Navy in 2010.
The Project 677 diesel submarine, developed by the Rubin design bureau, features an advanced anti-sonar coating for its hull, an extended cruise range, and advanced anti-ship and anti-submarine weaponry, including Club-S cruise missile systems.
The construction of the sub began in 1997 at St. Petersburg's Admiralty Shipyards. Two other submarines of the same class - the Kronshtadt and the Sevastopol - are being built by the company.
The Lada-class vessels will gradually replace the Kilo class submarines, which are sometimes called "Black Holes" for their ability to avoid detection, and are considered to be among the quietest diesel-electric submarines in the world.
The Russian Navy is planning to have a total of eight Lada-class submarines in the future.