Group : Attack Submarines
Status : Active
Also Known As : Project 671RTMK, Shuka (Soviet name), Victor III (NATO code)
Origin : Russia
Contractors : Admiralty Shipyards, Amur Shipyard
Initial Operational Capability (IOC) : 1978
Total Production : 26

The Project 671 is a class of nuclear-powered attack submarines deployed by the former Soviet Union between the late 1960s and early 1990s to engage submarines and surface ships. The whole Project 671 class comprises 48 ships in three versions: Project 671/Yersy/Victor I (15 ships 1968-1974), Project 671RT/Semga/Victor II (7 ships 1972-1978) and Project 671RTM/Shuka/Victor III (26 ships 1978-1992). Currently, Project 671RTM ships are the sole survivors of Project 671 submarine-class within the Russian Navy. Several of these ships are expected to remain in service with the Russian Navy until 2010/2015 when they should be phased out.

The Project 671RTM, Soviet name Shuka and NATO codename Victor III, is an improved version built on Project 671RT/Victor II design and aimed at reducing the acoustic signature over its predecessors. The lead ship was commissioned by the Soviet Navy in 1978. These ships are powered by two nuclear pressurized water reactors, were provided with four 21-inch torpedo tubes and two 25.6-inch torpedo tubes and feature improved communications and electronic gear. These ships are equipped with torpedoes and anti-ship/submarine missiles and several are fitted with Granat, Soviet name RKV-500 or NATO code SS-N-21 Sampson, land attack cruise missiles.

The Porject 671RTMK is an upgraded variant to be delivered to the Russian Navy in 2023.