Akuła (project 971 and 971M or other designations: Szczuka-B and Szczuka-M) are Soviet, and later Russian, nuclear-powered fighter submarines (ANN). The first unit of this class was launched in 1984. The units were built in the cities of Severodvinsk and Komsomolsk-on-Amur. The Akuła-class ship is 110-112 m long, and 13.5 m wide, and her underwater displacement ranges from approx. 10,500 to approx. 12,800 tons. The maximum underwater speed definitely exceeds 30 knots. The main armament of units of this class is eight 650 mm and 533 mm torpedo tubes.
The Akuła-class ships (project 971 and 971M) were constructed to complement the Sierra-class units and to replace the Victor-class submarines in the line. Units of this class are characterized by a very good silencing of the engine room and the use of anechoic hull plates (similarly to Oscar and Typhoon class ships), which significantly reduces the noise of ships of this class. The hull has very good hydrodynamic properties and was made of reinforced low-magnetic steel, which makes it difficult to detect the ship. Akuła-class units can also fire maneuvering rounds from a 650mm launcher. In modernized ships of this class (designation: Szczuka-M), the hull was slightly lengthened (up to 112 m) in order to even better soundproof the engine room, a layer of anechoic coatings on the inside of the hull and more modern electronic equipment was installed.