The Project 670A class (also known as Skat; ASCC/NATO codename Charlie I) was an SSGN of which 11 were completed between 1967 and 1972, all of which served in the Pacific Fleet. They were powered by one MV-4 reactor with an output of 89.2MW, displaced 4,300 tons surfaced and 5,100 tons submerged, and had a maximum speed of 20 knots on the surface and 24 knots submerged. Their Amethyst weapons system included eight launchers for P-70 anti-ship missiles – which could be fired while the vessel was submerged – and a floating radio buoy to receive commands, target designation data and satellite navigation data without coming to periscope depth. Other armament included four 533mm torpedo tubes forward and two 406mm tubes aft: the usual complement included two nuclear anti-ship torpedoes and two Tsakra (SS-N-15 Starfish) anti-submarine torpedoes. Boats of this class made 80 combat patrols in the 1970s and 1980s. K-43 was leased to India from January 1988 until January 1991, known there as Project 06709/INS Chakra. (Artwork by Ivan Zajac)