Akula-class submarine

The Akula class, Soviet designation Project 971 Shchuka-B (Russian: Щука-Б, lit. 'pike', NATO reporting name Akula) are a series of nuclear-powered attack submarines (SSNs) first deployed by the Soviet Navy in 1986. There are four sub-classes or flights of Shchuka-B, consisting of the original seven Project 971 boats (codenamed Akula I), commissioned between 1984 and 1990; six Project 971Is (Improved Akulas), commissioned between 1991 and 2009; one Project 971U (Akula II), commissioned in 1995; and one Project 971M (Akula III), commissioned in 2001. The Russians call all of the submarines Shchuka-B, regardless of modifications.

Some confusion may exist as the name Akula (Russian: Акула, meaning "shark" in Russian) was used by the Soviets for a different class of submarines, the Project 941, which is known in the West as the Typhoon class. The Project 971 was named Shchuka-B by the Soviets but given the designation Akula by the West after the name of the lead ship, K-284.

According to defense analyst Norman Polmar, the launch of the first submarine in 1985, "shook everyone [in the West] up", as Western intelligence agencies had not expected the Soviet Union to produce such a boat for another ten years.