On 9 December 1971, a single homing torpedo launched from beneath the Arabian Sea changed the course of a war. PNS Hangor, a French-built diesel-electric submarine nicknamed 'Shark,' sank an Indian Navy anti-submarine frigate that evening, achieving something no submarine had accomplished since the closing days of World War II: a confirmed kill of an enemy warship by a submerged vessel. Pakistan celebrates the anniversary as Hangor Day.
Negotiations for the Hangor began in 1966, part of the Pakistan Navy's strategic pivot after the 1965 war with India. Unable to match the Indian Navy's surface fleet expansion ship for ship, Pakistan focused on strengthening its Submarine Command. France designed and built the lead vessel of the Hangor class, a Daphne-type diesel-electric submarine. In 1969, Hangor was commissioned into service and sailed from Paris to her home base at the Karachi Naval Dockyard. She was placed under the command of Commander Ahmed Tasnim, with Lieutenant-Commander A.U. Khan as second-in-command, Lieutenant-Commander R.A. Kadri as electrical officer, and Lieutenant Fasih Bokhari handling navigation.
Hangor's first wartime deployment came in August 1971, gathering intelligence on Indian naval movements and clearing coastal waters around Manora Island and Ormara Bay. When full-scale war erupted in December, Tasnim positioned his submarine in the Arabian Sea off the Indian coast. The engagement on 9 December unfolded in three shots. The first homing torpedo was fired at INS Kirpan but failed to detonate due to a faulty mechanism — the moment it passed under the frigate without exploding, Kirpan turned and fled at maximum speed. As Kirpan ran, INS Khukri turned toward Hangor to mount a counterattack. A second torpedo found Khukri and detonated. The frigate sank in roughly two minutes, so fast that Hangor could not reach survivors in time. A third torpedo was later fired at Kirpan as she attempted a depth-charge counterattack; whether it struck her is disputed between Pakistani and Indian accounts. The strategic impact exceeded even the tactical victory: the Indian Navy cancelled its planned missile operation against Karachi scheduled for the following day. No submarine would sink another warship until the Falklands War in 1982, when HMS Conqueror sank the Argentine cruiser General Belgrano.
Hangor served the Pakistan Navy for 37 years, accumulating more operational gallantry awards than any other single warship in the fleet's history. She was decommissioned in 2006 and found a final berth as a museum ship in Karachi, where visitors can walk through the cramped compartments where Tasnim and his crew made history. The submarine has been featured in Pakistani dramas and films, including the movie Hangor S-131. Her story continues to resonate in both Pakistani and Indian popular culture, a reminder that beneath the surface of the Arabian Sea, a single vessel once altered the balance of a war.
Located at 24.885N, 67.091E near the Pakistan Maritime Museum on Karsaz Road in Karachi. PNS Hangor is now a museum ship on display at the maritime museum complex. Nearest airport is Jinnah International Airport (OPKC). The Karachi harbor and naval installations are clearly visible from medium altitude. Manora Island, where Hangor conducted pre-war patrols, is the narrow peninsula forming the harbor's southern boundary.