Echo - class submarine The Echo class were nuclear cruise missile submarine s of the Soviet Navy built during the 1960s . Their Soviet designation was Project 659 for the first five vessels , and Project 675 for the following twenty - nine . Their NATO reporting name s were " Echo I " and " Echo II " . All were decommissioned by 1994 . Echo I class . The Soviet Echo I class ( Project 659 class ) were completed at Komsomolsk in the Soviet far east in 1960 to 1963 . The Echo I class were classed as SSGNs armed with six launchers for the P - 5 Pyatyorka ( SS - N - 3C , " Shaddock " ) land - attack cruise missile . The Echo I class had to operate in a strategic rather than anti - shipping role because of the lack of fire control and guidance radars . As the Soviet SSBN force built up , the need for these boats diminished so they were converted to the Project 659T SSN ' s between 1969 and 1974 . The conversion involved the removal of the cruise missiles , the plating over and the streamlining of the hull to reduce underwater noise of the launchers and the modification of the sonar systems to the standard of the SSNs . All the Echo Is were deployed in the Pacific Fleet although " K - 122 " was damaged by a fire in compartment VII during a patrol mission near Okinawa in August 1980 and had to be towed back to Vladivostok for emergency dry docking ( the submarine was removed from active service in October 1985 ) . The last two boats were scrapped in the early 1990s . Echo II class . The Echo II class ( Project 675 class ) were built at Severodvinsk ( 18 vessels ) and Komsomolsk ( 11 vessels ) between 1962 and 1967 as anti - carrier missile submarines . The Echo II class carried eight P - 6 ( SS - N - 3a " Shaddock " ) anti - ship cruise missiles mounted in pairs above the pressure hull . To fire the missiles , the ship had to surface and the missile was elevated to 15 degrees . The Echo II class also had fire control and guidance radar . The Echo II class could fire all eight missiles in 30 minutes , but would have to wait on the surface until the missile mid - course correction and final target selection had been sent unless guidance had been handed over to a third party . From the mid - 1970s , fourteen of the 29 Echo II class were converted during overhauls to carry the P - 500 Bazalt ( SS - N - 12 " Sandbox " ) anti - ship cruise missile , with a range of . The conversions ( Project 675M ) could be distinguished by the fitting bulges either side of the sail . Three of these modified units were further upgraded under Project 675MKV towards the end of the Cold War . The P - 1000 Vulkan ( GRAU 3M70 ) flies faster ( Mach 2 . 3 - 2 . 5 ) than the P - 500 and its range was extended to . It replaces steel components with titanium to reduce weight , and has an improved propulsion system . It appears to have used a similar fire - control system to the P - 500 , the Argon - KV and Argument radar . P - 1000 was installed on three units of the Northern Fleet between 1987 and 1993 ; the conversion of two boats of the Pacific Fleet , the K - 10 and K - 34 , was abandoned due to lack of funds . The Echo II class were divided evenly between the Pacific and Northern Fleets . The boats were obsolete by the mid - 1980s , and were deleted in 1989 and 1995 . Accidents . Submarines of the Echo class were involved in several accidents :