The India–Pakistan naval war of 1971 refers to the maritime military engagements between the Indian Navy and the Pakistan Navy during the Indo-Pakistani War of 1971. The series of naval operations began with the Indian Navy's exertion of pressure on Pakistan from the Indian Ocean, while the Indian Army and Indian Air Force moved in to choke Pakistani forces operating in East Pakistan on land. Indian naval operations comprised naval interdiction, air defence, ground support, and logistics missions.
Background
The Indian Navy did not play a major role during the Indo-Pakistani War of 1965 as the war focused on land-based conflict. On 7 September, a flotilla of the Pakistan Navy under the command of Commodore S.M. Anwar carried out a bombardment, Operation Dwarka, of the Indian Navy's radar station of Dwarka, 200 miles (320 km) south of the Pakistani port of Karachi. While there was no damage to the radar station, this operation caused the Indian Navy to undergo a rapid modernization and expansion. Consequently, the Indian Navy budget grew from ₹ 350 million to ₹ 1.15 billion. The Indian Navy added a squadron to its combatant fleet by acquiring six Osa-class missile boats from the Soviet Union. The Indian Naval Air Arm was also strengthened.
Pakistani Navy in East Pakistan
The Eastern Command was established in 1969 and Rear-Admiral Mohammad Shariff (later four-star Admiral) was made naval commander in that region. Admiral Shariff administratively ran the Navy, and was credited for leading the administrative operations. Under his command, SSG(N), Pakistan Marines and SEAL teams were established, running both covert and overt operations in the Eastern Command and were assumed command by Commander David R. Felix.During the conflict, East Pakistan's naval ports were left defenceless as the Eastern Command of Pakistan had decided to fight the war without the navy. Faced with overwhelming opposition, the navy planned to remain in the ports when war broke out.
The Pakistan Naval Forces had inadequate ships to challenge the Indian Navy on both fronts, and the Pakistan Air Force (PAF) was unable to protect these ships from the Indian Air Force (IAF) and Indian Naval Air Arm. Furthermore, Chief of Naval Staff of Pakistan Navy, Vice-Admiral Muzaffar Hassan, had ordered the navy to deploy all naval power on the Western Front. Most of the Pakistan Navy's combatant vessels were deployed in West Pakistan and only one destroyer, PNS Sylhet, was assigned in East Pakistan, on the personal request of Admiral Shariff. faced with a hopeless task against overwhelming odds, the Navy planned to remain in port when war broke out.
In the eastern wing, the Pakistan Navy heavily depended on her gun boat squadron. The Pakistan's Eastern Naval Command was in direct command of Flag Officer Commanding (FOC) Rear-Admiral Mohammad Shariff who also served as the right-hand of Lieutenant-General Niazi. The Pakistan Navy had four gunboats (PNS Jessore, Rajshahi, Comilla, and Sylhet). All were 345 ton vessels, capable of attaining a maximum speed of 20 knots, crewed by 29 sailors, and fitted with 40/60 mm. cannons and machine guns.One additional patrol boat (PNS Balaghat) and 17 armed boats (armed with 12.7mm./20mm. guns and/or .50 or .303 Browning machine guns) were also employed, in addition to numerous civilian-owned boats requisitioned and armed with various weapons by Pakistani forces, were also part of the Pakistani naval contingent.
This flotilla of improvised armed boats were adequate for patrolling and anti-insurgency operations, but hopelessly out of place in conventional warfare. Before the start of hostilities in December, PNS Jessore was in Khulna with 4 other boats, PNS Rajshahi, PNS Comilla, and PNS Balaghat were at Chittagong, and PNS Sylhet was undergoing repairs at a dry-dock near Dhaka. The outbreak of hostilities on 3 December found most of these boats scattered around the province.
Commencement of naval hostilities
On 4 December, three Indian Navy missile boats, equipped with P-15 Termit anti-ship missiles, launched Operation Trident against the port of Karachi. In 1971, Karachi not only housed the headquarters of the Pakistan Navy but was also the backbone of Pakistan's economy, as it served as the hub of Pakistan's maritime trade, meaning that any potential blockade of Karachi would be disastrous for Pakistan's economy. The defence of Karachi harbour was therefore paramount to the Pakistani High Command and it was heavily defended against any airstrikes or naval strikes. The Pakistani Navy had launched submarine operations to gather intelligence on Indian naval efforts. Even so, with multiple intelligence reports by the submarines, the Navy had failed to divert the naval attacks, due to misleading intelligence and communications.
The Indian Navy's preemptive strike resulted in an ultimate success. The Indian missile vessels, of the 25th missile boat squadron, successfully sunk the minesweeper PNS Muhafiz, the destroyer PNS Khaibar and MV Venus Challenger which, according to Indian sources, was carrying ammunition for Pakistan from the United States forces in Saigon. The destroyer PNS Shah Jahan was damaged beyond repair. The missile ships also bombed the Kemari oil storage tanks of the port which were burnt and destroyed causing massive loss to the Karachi Harbour. Operation Trident was an enormous success with no physical damage to any of the ships in the Indian task group, which returned safely to their garrison.
Pakistan's Airforce retaliated by bombing Okha harbour, scoring direct hits on fuelling facilities for missile boats, ammunition dump and the missile boats jetty. Though India had anticipated this assault and moved their missile boats to other locations prior thus preventing any losses, the destruction of the special fuel tank prevented any further incursions until Operation Python. On the way back from the bombing the PAF aircraft encountered an Alizé 203 Indian aircraft and shot it down.
Naval operations in the Eastern theatre
On 4 December 1971, the aircraft carrier Vikrant was also deployed and its Hawker Sea Hawk attack aircraft contributed to Air Operations in East Pakistan. The aircraft successfully attacked many coastal towns in East Pakistan including Chittagong and Cox's Bazar. The continuous attacks later destroyed the PAF's capability to retaliate.
The Pakistan Navy responded by deploying her ageing long-range submarine, PNS Ghazi, to counter the threat as the Naval Command had overruled the objections by her officers. Ghazi, under the command of Commander Zafar Muhammad Khan, was assigned to locate Vikrant, but when it was not able to locate, decided to mine the port of Visakhapatnam – the headquarters of Eastern Naval Command. The Indian Navy's Naval Intelligence laid a trap to sink the submarine by giving fake reports about the aircraft carrier. At around midnight of 3–4 December, Ghazi began its operation of laying mines. The Indian Navy dispatched INS Rajput to counter the threat.
Rajput's sonar radar reported the disturbance underwater and two depth charges were released. The deadly game ended when the submarine sank mysteriously while laying a mine with all 92 hands on board around midnight on 3 December 1971 off the Visakhapatnam coast.The sinking of Ghazi turned out to be a major blow and setback for Pakistani naval operations in East Pakistan.
On 5/6 December 1971, naval air operations were carried out Chittagong, Khulna, and Mangla harbours, and at ships in the Pussur river. The oil installations were destroyed at Chittagong, and the Greek merchant ship Thetic Charlie was sunk at the outer anchorage. On 7/8 December, the airfields of PAF were destroyed, and the campaign continued until 9 December. On 12 December, Pakistan Navy laid naval mines on amphibious landing approaches to Chittagong. This proved a useful trap for some time, and it had denied any direct access to Chittagong port for a long time, even after the instrument of surrender had been signed. The Indian Navy therefore decided to carry out an amphibious landing at Cox's Bazar with the aim cutting off the line of retreat for Pakistan Army troops. On 12 December, an additional amphibious battalion was aboard INS Vishwa Vijaya was sailed from Calcutta port. On the night of 15/16 December, the amphibious landing was carried out, immediately after IAF bombardment of the beach a day earlier. After fighting for days, the human cost was very high for Pakistani forces, and no opposition or resistance was offered by Pakistani forces to Indian forces. During this episode Eastern theatre Indian forces suffered only 2 deaths in the operation. Meanwhile, Pakistani forces were reported to have suffered hundreds of deaths. By the dawn of 17 December, the Indian Navy was free to operate at will in the Bay of Bengal.
Elimination of gunboat threats
Indian carrier-borne aircraft attacked the Rajshahi and Comilla near Chittagong on 4 December, with the Rajshahi damaged and the Comilla sunk. The Balaghat, which was not attacked, rescued the Comilla crew and returned to Chittagong with the surviving ships. On 5 December, Indian planes sank two patrol boats in Khulna. The PNS Sylhet was destroyed on 6 December and the Balaghat on 9 December by Indian aircraft.
The 39th Division (under General Rahim Khan) Headquarters at Chandpur had requested evacuation by river on 8 December. Under the escort of a gunboat, the flotilla, made up of local launches, sailed in the early hours of 10 December. The IAF spotted and bombed the ships, and PNS Jessore, which had withdrawn from Khulna to Dhaka, was destroyed escorting boats evacuating Pakistani troops from Chandpur while other boats were either sunk or beached themselves and failed to reach Dhaka. The survivors later were evacuated by ships and helicopters operating at night. PNS Rajshahi was repaired, and under the command of Lt. Commander Sikander Hayat, managed to evade the Indian blockade and reach Malaysia before the surrender on 16 December. From there, it sailed to Karachi and continued to serve in the Pakistan navy.
Sinking of INS Khukri
As the Indian military offensive in East Pakistan increased, the Pakistan Navy had dispatched her entire submarine squadron on both fronts. Codename "Operation Falcon", the Pakistan Navy began their reconnaissance submarine operations by deploying PNS Hangor, a Daphné-class submarine, near the coastal water of West-Pakistan, and PNS Ghazi, a Tench-class long range submarine, near the coastal areas of East-Pakistan.
According to the Lieutenant R. Qadri, an electrical engineer officer aboard Hangor during the time, the assigned mission was considered quite difficult and highly dangerous, with the submarine squadron sailing under the assumption that the dangerous nature of this mission meant a great mortal risk to the submarine and her crew. On the midnight of 21 November 1971, PNS Hangor, under the command of Commander Ahmed Tasnim, began her reconnaissance operations. Both PNS Ghazi and PNS Hangor maintained coordination and communication throughout patrol operations. On 2 and 3 December, Hangor had detected a large formation of ships from Indian Navy's Western fleet which included cruiser INS Mysore. Hangor had passed an intelligence to Pakistan naval forces of a possible attack by the observed Indian Armada near Karachi. The Indian Naval Intelligence intercepted these transmissions, and dispatched two anti-submarine warfare frigates, INS Khukri and INS Kirpan of 14th Squadron – Western Naval Command.
On 9 December 1971, at 1957 hours, Hangor sunk Khukri with two homing torpedoes. According to her commander, the frigate sank within the matter of two minutes. The frigate sank with 192 hands on board. Hangor also attacked INS Kirpan on two separate occasions, but the torpedoes had missed their target. Kirpan quickly disengaged and successfully evaded the fired torpedoes.