PNS Ghazi PNS " Ghazi ( previously USS " Diablo " ( SS - 479 ) ; reporting name : Ghazi " ) was a " Tench " - class diesel - electric submarine and the first ever attack submarine of Pakistan Navy ( PN ) , leased from United States in 1963 . She saw action in the 1965 and 1971 wars between India and Pakistan . The submarine could be armed with up to 28 torpedoes and , in later years , was re - fitted in Turkey for mine - laying capability . Starting from being the only submarine in the war theater in 1965 , it remained the Pakistan Navy ' s flagship submarine until she sank near the eastern coast of India during the 1971 Indo - Pakistani War en route to the Bay of Bengal under mysterious circumstances . The Indian Navy credits " Ghazi ' s " sinking to the destroyer INS " Rajput " ; however , Pakistan ' s official sources state that " the submarine sank due to either an internal explosion or accidental detonation of mines being laid by the submarine off the Vishakapatnam harbour " with neutral sources confirming " Rajput " still in its port when the submarine sank . Service with United States Navy . USS " Diablo " ( SS / AGSS - 479 ) , a " Tench " - class submarine , was the only ship of the United States Navy to be named for the diablo , a member of the batfish family , common in the West Indies and along the southern coast of the United states . Her keel was laid down by the Portsmouth Navy Yard . She was launched on 1 December 1944 sponsored by Mrs . V . D . Chapline , and commissioned on 31 March 1945 with Lieutenant Commander G . G . Matherson in command . " Diablo " arrived at Pearl Harbor from New London , Connecticut , on 21 July 1945 . She sailed for her first war patrol 10 August with instructions to stop at Saipan for final orders . With the cease fire , her destination was changed to Guam where she arrived 22 August . On the last day of the month she got underway for Pearl Harbor and the East Coast arriving at New York City on 11 October . Except for a visit to Charleston , South Carolina , in October , she remained at New York until 8 January 1946 . From 15 January 1946 to 27 April 1949 " Diablo " was based in the Panama Canal Zone participating in fleet exercises and rendering services to surface units in the Caribbean Sea . From 23 August to 2 October 1947 she joined and for a simulated war patrol down the west coast of South America and around Tierra del Fuego . The three submarines called at Valparaíso , Chile , in September while homeward bound . " Diablo " sailed to Key West , Florida , for antisubmarine warfare exercises , from 16 November to 9 December 1947 , and operated from New Orleans , Louisiana , for the training of naval reservists in March 1948 . " Diablo " arrived at Naval Station Norfolk , Norfolk , Virginia , her new home port , 5 June 1949 , and participated in Operation " Convex " in 1951 , and alternated training cruises with duty at the Sonar School at Key West . Her home port became New London in 1952 and she arrived there 17 September to provide training facilities for the Submarine School . From 3 May to 1 June 1954 she was attached to the Operational Development Force at Key West for tests of new weapons and equipment . She participated in Operation " Springboard " in the Caribbean from 21 February to 28 March 1955 , and continued to alternate service with the Submarine School with antisubmarine warfare and fleet exercises in the Caribbean and off Bermuda , as well as rendering services to the Fleet Sonar School and Operational Development Force at Key West . Between February and April 1959 she cruised through the Panama Canal along the coasts of Colombia , Ecuador , Peru , and Chile for exercises with South American navies . On 27 May 1960 she entered Philadelphia Naval Shipyard for an overhaul which continued through October 1960 . Originally launched in 1944 as the , a long - range built by the Portsmouth Navy Yard . She was launched on 1 December 1944 , and commissioned on 31 March 1945 . In 1962 , her hull classification symbol was changed to " AGSS - 479 " . In 1963 , " Diablo " was transferred to the Pakistan on a four - year lease under the terms of the Security Assistance Program . After an extensive overhaul and conversion to Fleet Snorkel configuration in the United States , she was commissioned into the Pakistani Navy as PNS " Ghazi " on 1 June 1964 . She reported for duty in Karachi in September of that year . Service with Pakistan Navy . " Ghazi " was the first submarine to be operated by a navy in the Indian subcontinent becoming a serious threat to the Indian Navy . 1965 war . " Ghazi " , the only submarine in the conflict arena , was deployed in the Indo - Pakistani war of 1965 to attack heavy ships of the Indian Navy , and the ships aiding Operation Dwarka . Though the submarine did not score any hits , it was a significant threat to any ships that came out of harbour ( with that being its mission ) , but none came out . It won 10 awards including two decorations of Sitara - e - Jurat and the President ' s citations . The commanding officer Commander Karamat Rahman Niazi ( later 4 - star admiral ) , second - in - command Lieutenant Commander Ahmed Tasnim , and Lieutenant Zafar Muhammad Khan won a Sitara - e - Jurat . After the war , the submarine was sent to Turkey for a $ 1 . 5 million refit in 1967 - 68 . Her spares were to be provided from Turkish stocks . 1971 war . Sensing a deteriorating military scenario with the transfer of Indian aircraft carrier close to East Pakistan , the Pakistan Military decided to negate the threat by deploying its flagship submarine . On 14 November , " Ghazi " sailed out of harbour on a reconnaissance patrol under the command of Cdr . Zafar Muhammad Khan with 92 hands on board . It was expected to report on 26 November . The submarine sailed 3 , 000 miles ( 4 , 828 kilometres ) around the Indian peninsula from the Arabian Sea to the Bay of Bengal . After the Indo - Pakistani war of 1965 , Indian Navy went to a rapid program of modernization and expansion due the success of Operation Dwarka carried out by Pakistan Navy . Pakistan ' s Eastern Naval Command Flag Officer Commanding Rear - Admiral Mohammad Shariff had proposed the idea of deploying of single combatant squadron of warships and strengthening the naval defense of East - Pakistan . The Naval Combatant Headquarters of the Pakistan Navy considered the proposals till the end of the year of 1971 . None were considered feasible and the Pakistan Navy in the eastern theater was in no position to counter the Indian naval challenge by the end of the year . Pakistan ' s response to Indian military deployments around East Pakistan were a series of " ad hoc " measures , taken from time to time . Dispatch of " Ghazi " to India ' s eastern seaboard , not part of the original plans , was one such step taken at the insistence of the Pakistan military high command to reinforce Eastern Command . The Pakistan Army ' s Combatant Headquarter , the GHQ , mounted pressure on the Pakistan Navy to extend the sphere of its operations into the Bay of Bengal . This increased with the growth of Indian and Indian - inspired naval activities in and around East Pakistan . " Ghazi " , aging but being the only submarine which had the range and capability to undertake operations in the distant waters under control of the enemy , was pressed into operation to destroy or damage " Vikrant " . The officer in command of the submarine service branch of the Pakistan Navy and the junior officers and commander of " Ghazi " had objected to the plan as it was proposed by the army and naval officers during the briefing session . It was difficult to sustain such naval operations in a distant area of Bay of Bengal , in the total absence of repair , logistics and recreational facilities in the vicinity . At this time , submarine repair facilities were totally absent at Chittagong — the only Pakistani sea port in the east during this period . To her earlier commanders , the mission was considered highly dangerous and impossible to achieve by sending an obsolete submarine behind enemy lines . The commanders at NHQ overruled the objections , and instead planned a reconnaissance operation , which led to launching of the submarine operations in the eastern theater . Per the recommendation of senior naval officers and commanders , " Ghazi ' s " command was changed immediately to the newer and younger naval officers . On 14 November 1971 , " Ghazi " sailed out from her base under the new command of Commander Zafar Muhammad Khan , who was promoted to this rank 4 days before , with 92 men aboard . Fate . The mysterious sinking of " Ghazi " took place somewhere around 4 December 1971 during Pakistani Navy ' s submarine assault on the aircraft carrier " Vikrant " and / or mine - laying mission on Vishakapatnam Port , Bay of Bengal . On 14 November 1971 , " Ghazi " sailed out of harbour on a reconnaissance patrol mission under the command of Cdr . Zafar Muhammad Khan with 93 hands on board . It was expected to report on 26 November . Deployment of " Ghazi " was part of Pakistan Navy reconnaissance operations in Arabian sea and Bay of Bengal . The " Ghazi " was 400 miles off Bombay on 16 November , off Ceylon on 19 November , and entered the Bay of Bengal on 20 November 1971 . She started looking for the " Vikrant " on 23 November off Madras but was not aware that she was 10 days too late and the " Vikrant " was actually somewhere near the Andaman islands . Vice Admiral Krishnan sent for Captain Inder Singh , the commanding officer of the " Rajput " for detailed briefing at about 16 : 00 on 1 December and told him that a Pakistani submarine had been sighted off Ceylon and was absolutely certain that the submarine would be somewhere around Madras / Vishakapatnam . He made it clear that once " Rajput " had completed refueling , she must leave the harbor with all navigational aids switched off . At 23 : 40 on 3 December , taking on board a pilot , " Rajput " moved through the channel to the exit from Vishakhapatnam . Exactly at midnight , shortly after passing the entrance buoy , starboard lookout reported breaker on the surface of the water right on the nose . Singh , changing the course at full speed across the specified point and ordered to lose at this point , two depth charges , and that was done . The explosions were " stunning " , and the ship suffered a serious concussion . However , visible results of this attack are not given . " Rajput " for some time surveyed the area dumping bombs , no longer found any contact — either visual or acoustic . A few minutes later the destroyer continued on her way to the coast of East Pakistan . " Ghazi " sank with all 92 hands on board due to unknown circumstances off the Vishakapatnam coast , allowing the Indian Navy to effect a naval blockade of then East Pakistan ( now Bangladesh ) . Intelligence and deception . According to Indian Vice Admiral Mihir K . Roy , who was Director of Intelligence during this period , its existence was revealed when signal addressed to naval authorities in Chittagong was intercepted , requesting information on a lubrication oil only used by submarines and minesweepers . Management from the Indian Navy began to realize that the Pakistanis would inevitably be forced to send in the Bay of Bengal their submarine " Ghazi " as the sole ship which could operate in these waters . At that time , Vice Admiral N . Krishnan was the Flag officer Commander - in - Chief of the Indian Navy ' s eastern Naval Command . From his point of view , it was pretty clear that Pakistan would have deployed the " Ghazi " in the Bay of Bengal and a part of its plan was an attempt to sink the Indian aircraft carrier " Vikrant " . Fearing a possible attack primarily against its own aircraft carrier deployed in the region , Indian commanders had taken early action , in the period preceding the outbreak of hostilities , to slip " Vikrant " aircraft carrier groups at a secret anchorage in the Andaman Islands , designated as " X - Ray " . On 13 November , " Vikrant " with escort ships went from Madras to this point . At the same time concerted action was taken to disseminate information designed to mislead the enemy about the true location of the aircraft carrier , and to foster confidence that the carrier was stationed at Visakhapatnam . Contracts were placed for delivery in Visakhapatnam of large quantities of food , especially meat and fresh vegetables , allegedly destined for the Eastern Fleet ships . A private telegram was allegedly sent from Vishakhapatnam from one of the sailors of the aircraft carrier , inquiring about the health of his ailing mother . All these activities were apparently successful in deceiving the enemy . 25 November , the Pakistani command sent communication to the " Ghazi " saying that " intelligence indicates the finding of an aircraft carrier in port " . Aftermath . " Ghazi " was expected to report back to Karachi Naval dockyard on November 26 of 1971 . Commanding officer of " Ghazi " , Commander Zafar Muhammad Khan was ordered to submit a report over the mission ' s course . On November 26 , " Ghazi " failed to return to her base , and the base commander had repeatedly sent communication signals to " Ghazi " , but they weren ' t answered . Anxiety grew day by day at the Naval Combatant Headquarter , The NHQ . Desperate for her return to the base , the NHQ had pressed frantic efforts to establish communications with the " Ghazi " , but they too failed . Before the 1971 naval hostilities broke out , earlier commanding officers and submariners of " Ghazi " had doubted about the fate of the submarine had already begun to agitate the minds of submariners and many senior officers at Naval Headquarters ( NHQ ) . The NHQ commanders attributed to their junior officers that several reasons could , however , be attributed to the failure of the submarine to communicate . On December 9 , Indian Navy strangely issued a statement about the fate of " Ghazi " . The first indication of " Ghazi " ' s tragic fate came when a message by NHQ of India , claiming sinking of " Ghazi " on the night of 3 December , was intercepted . The Indian NHQ issued the statement few hours before the loss of INS " Khurki " , and prior to launch of Operation Python . Neutral witnesses . An independent testimony stems from an Egyptian officer who claimed that the Indian ships were docked at the Visakhapatnam harbour when the explosions from the supposed Indian sinking of " Ghazi " occurred , and that " it was not until about an hour after the explosion that two Indian naval ships were observed leaving harbour " . Pakistani version . According to Pakistan ' s Naval Intelligence ( NI ) , the " Ghazi " sank when the mines it was laying were accidentally detonated . Another more plausible theory , also favored by Pakistan , is that the explosive shock from one of the depth charge s set off the torpedo es and mines ( some of which may have been armed for laying ) stored aboard the submarine . The Pakistani Naval Command counter argued : the " Ghazi " itself may have inadvertently passed over the mines during the mine laying operations ; patrolling Indian vessels or Indian depth charges may also have tripped the count mechanism of one or more mines . One of the reasons to believe this as true is that Indian divers found the damaged parts of the submarine to be blown inside out . The Hamoodur Rahman commission , which was constituted by Pakistan Government to investigate the military and political causes of the country ' s defeat in the 1971 war , never carried out an investigation into the incident . Indian version . After the war India undertook an investigation into the incident . India claimed that the submarine was sunk following a series of successful manoeuvres by the Indian Navy . Later some items of the ship like the logbook and official Pakistani tapes , were displayed in India ' s Eastern Naval Command . A submarine rescue vessel , INS " Nishtar " was sent to check the debris . India later built a " Victory Memorial " on the coast near where the " Ghazi " was sunk . The official history of Indian Navy ‘ Transition to Triumph ’ , authored by Vice - Admiral ( Retd ) G M Hiranandani , quotes naval records and top naval officials who commanded operations on the eastern waterfront as saying that INS " Rajput " was sent from Vizag to track down " Ghazi " . The book also noted that the time of dropping of the charges , the explosion which was heard by the people of Vizag and that of a clock recovered from " Ghazi " , matched . Admiral Roy of India states : " The theories propounded earlier by some who were unaware of the " ruse de guerre " ( attempt to fool the enemy in wartime ) leading to the sinking of the first submarine in the Indian Ocean gave rise to smirks from within our own ( Indian ) naval service for an operation which instead merited a " Bravo Zulu " ( flag hoist for bravery ) " . Admiral S . M . Nanda , who commanded the Indian Navy during the 1971 Indo - Pak War , states : " In narrow channels , ships , during an emergency or war , always throw depth charges around them to deter submarines . One of them probably hit the " Ghazi " . The blow - up was there , but nobody knew what it was all about until the fisherman found the lifejacket " . Recovery of sunk vessel . Following this both the United States and the Soviet Union offered to raise the submarine to the surface at their own expense . The Government of India , however , rejected these offers and allowed the submarine to sink further into the mud off the fairway buoy of Vishakapatnam .