SOSUS SOSUS , an acronym for Sound Surveillance System , is a chain of underwater listening posts located around the world in places such as the Atlantic Ocean near Greenland , Iceland and the United Kingdom — the GIUK gap , and at various locations in the Pacific Ocean . The United States Navy ' s initial intent for the system was for tracking Soviet submarines , which had to pass through the gap to attack targets further west . It was later supplemented by mobile assets such as the Surveillance Towed Array Sensor System ( SURTASS ) , and became part of the Integrated Undersea Surveillance System ( IUSS ) . History . SOSUS development was started in 1949 when the US Navy formed the Committee for Undersea Warfare to research anti - submarine warfare . The panel allocated $ 10 million annually to develop systems to counter the Soviet submarine threat consisting primarily of a large fleet of diesel submarines . They decided on a system to monitor low - frequency sound in the SOFAR channel using multiple listening sites equipped with hydrophones and a processing facility that could detect submarine positions by triangulation over hundreds of miles . Research phase . At MIT in 1950 , the committee sponsored Project Hartwell , named for the Hartwell Farms restaurant in Lexington , MA , where some of the initial steps were planned . In November , they selected Western Electric to build a demonstration system , and the first six element hydrophone array was installed on the island of Eleuthera in the Bahamas . Meanwhile Project Jezebel at Bell Labs and Project Michael at Columbia University focused on studying long range acoustics in the ocean . By 1952 , enough progress resulted in top secret plans to deploy six arrays in the North Atlantic basin , and the classified name SOSUS was used . The number of arrays was increased to nine later in the year , and Royal Navy and USN ships , including USS " Neptune " and USS " Peregrine " , started laying the cabling under the cover of Project Caesar . In 1953 , Jezebel ' s research had developed an additional high - frequency system for direct plotting of ships passing over the stations , intended to be installed in narrows and straits , called Project Colossus . SOSUS goes operational . In 1961 , SOSUS tracked the Fleet Ballistic Missile ( FBM ) submarine USS " George Washington " ( SSBN - 598 ) from the US to the UK . The next year SOSUS detected and tracked its first Soviet diesel submarine . Later that year the SOSUS test system in the Bahamas tracked a Soviet Foxtrot class submarine during the Cuban Missile Crisis . SOSUS was upgraded a number of times as submarines became quieter . SOSUS systems consisted of bottom mounted hydrophone arrays connected by underwater cables to facilities ashore . The individual arrays were installed primarily on continental slopes and seamounts at locations optimized for undistorted long range acoustic propagation . The combination of location within the ocean and the sensitivity of arrays allowed the system to detect acoustic power of less than a watt at ranges of several hundred kilometres . ( The system is so sensitive that it can even detect the presence of Soviet / Russian Tu - 95 Bear 4 - engine bombers flying overhead ; the tips of the bombers ' s long propellers exceed the speed of sound , creating sonic booms as they spin around . These sonic booms reach the surface of the ocean below , which then transmits the sonic shocks to the underwater hydrophones . ) SOSUS monitoring stations were known as Naval Facilities ( NAVFAC , not to be confused with the Naval Facilities Engineering Command that has the same acronym . ) NAVFACs existed in the west at NAS Adak , Alaska ; Pacific Beach , Washington ; Coos Bay , Oregon ; NAVFAC Centerville Beach near Eel River , California ; NAVFAC Point Sur near Monterey , California ; Naval Outlying Field San Nicolas Island , California ; and Naval Air Station Whidbey Island , Washington . In the east , they were deployed at Tom Nevers Naval Facility Nantucket , Massachusetts ; Lewes , Delaware ; Cape Hatteras , North Carolina ; and Ramey Air Force Base , later Naval Facility Punta Borinquen , Puerto Rico . Other NAVFACs were located in the Pacific at NAS Barbers Point , Hawaii ; NAF Midway Island ; and Naval Base Guam , while additional Atlantic locations expanded to include NAS Keflavik , Iceland ; CFS Shelburne , Nova Scotia and Naval Station Argentia , Newfoundland ( both later remoted to CFB Halifax , Nova Scotia ) ; NAVFAC Brawdy , Wales ; Joint Maritime Facility St . Mawgan , Cornwall ; Antigua ; Maritime Data Centre Gibraltar , UK ; NAVFAC Barbados ; NAVFAC Eleuthera , Bahamas ; NAVFAC San Salvador , Bahamas ; NAVFAC Bermuda ; and NAVFAC Grand Turk . Evaluation Centers were also set up at NAS Whidbey Island , Washington and NAS Oceana / Dam Neck Annex , Virginia in the early 1980s . The Data Evaluation Center at Dam Neck was named after Commander Will James whose entire Navy career was spent in the system . LOFAR ( frequency analysis ) was carried out on the signals from the arrays and paper outputs called " lofargrams " were produced which were used to help detect and classify contacts . A moving electronic stylus burned signatures of the sounds picked up from the ocean onto long rolls of paper . Naval personnel who monitored these lofargrams for submarine activity were called OTs ( Ocean System Technicians . ) Signatures at certain frequencies would point to the possibility of a submarine and aircraft would then be called to verify the position in the ocean . Besides this group of four or more enlisted personnel was also a watch captain , usually a lower ranking officer or a chief petty officer . Also on this 24 hour watch were two radiomen to handle communications . When the sank in 1963 , SOSUS helped determine its location . In 1968 , the first detections of Victor and Charlie class Soviet submarines were made , while in 1974 the first Delta class submarine was observed . In 1968 , SOSUS played a key role in locating the wreckage of a US Nuclear Attack submarine , the USS Scorpion ( SSN - 589 ) , lost near the Azores in May . Moreover , SOSUS data from March 1968 facilitated the discovery , and clandestine retrieval 6 years later , of parts of a Soviet GOLF II - class ballistic missile submarine , the K - 129 , that foundered that month north of Hawaii . In 1985 , the Fixed Distributed System ( FDS ) test array became operational and the first SURTASS patrol began . The name for the overall system had become Integrated Undersea Surveillance System ( IUSS ) . In 1991 , the system mission was declassified and the next year it began reporting whale detections and SOSUS work stations began replacing paper lofargrams . The Advanced Deployable System became operational as part of IUSS in 1996 . SOSUS after the Cold War . SOSUS was gradually condensed into a smaller number of monitoring stations during the 1970s and 1980s . However , the SOSUS arrays themselves were based upon technology that could only be upgraded irregularly . With the ending of the Cold War in the 1990s , the immediate need for SOSUS decreased , and the focus of the US Navy also turned toward a system that was deployable on a theatre basis . In effect , the end of the Cold War eliminated much of the justification for maintaining IUSS at its full capability , with the existence and capabilities of SOSU and IUSS being declassified in 1991 . Although officially declassified in 1991 , by that time IUSS and SOSUS had long been an open secret . Alternate or dual - use partnerships exist with the University of Washington Applied Physics Laboratory for Ocean Acoustic Tomography , NOAA VENTS , Woods Hole Oceanographic Institute , Texas ARL , and several other organizations . Commander , Undersea Surveillance ( CUS ) , operates as the immediate superior in command ( ISIC ) for all IUSS sites , whereas operational command of those same sites is held by COMSUBPAC .