The Indian Navy is set receive the Nerpa Akula-II Class nuclear attack submarine from Russia following its final pre-commissioning trials, which will begin on 15 November 2009.

According to officials the submarine has no unresolved issues, and the pre-commisioning sea trials would be used to fix only minor flaws.

The Nerpa, which will be rechristened as INS Chakra by the Indian Navy, will enter service in early 2010, after which the Russian instructors will train the Indian naval crew.

On 8 November 2008, Nerpa met with an accident during an underwater test run in the Pacific Ocean that killed 21 sailors and technical staff after toxic gas was released from the fire suppression system.

The submarine is being acquired on a ten-year lease from Russia, at the cost of $650m.