Moskit (Osa) boats firing missile on Karachi city in the 1971 Bangladesh freedom war

Every year, India celebrates December 4 as Navy Day to commemorate Operation Trident - a key offensive during the Indo-Pak War of 1971, which is regarded as one of the greatest sea-faring successes in Indian naval history.

Naval warfare has a long and illustrious history in India. Since Rajendra Chola's 10th-century maritime expedition to Southeast Asia and Maratha Admiral Kanhoji Angre's 18th-century naval wars against the British, Dutch, and Portuguese, Indian ships have made their presence felt.

The Indian Navy has played a pivotal role in at least four major military operations after 1947, extending the country's pedigree of prominent military feats. The Indian Navy's annals encompass multiple narratives that illustrate why it has earned the distinction of being a game-changer. However, the most recognized and celebrated naval operation commemorated on December 4 every year as Indian Navy Day is - Operation Trident.

Let us revisit this naval operation that proved to be a turning point in the 1971 War between India and Pakistan:

In the last 1960s, war clouds were looming large. The Indian Navy, at that point, acquired the Osa-I missile boats from the Soviet Union. Equipped with deadly ship-to-ship Styx missiles, these boats could take down even the most powerful enemy cruisers in the high seas. The ships were also armed with rang-out homing radars, which could out-range any naval radar during that era. As a result, these fast-moving missile boats could strike deep.

However, a significant downfall was their narrow range, making them ideal only for coastal defence. The Indian Navy still went ahead and purchased eight Osa-Is, formed a squadron for these missiles boats, and sent them to Russia for an eight-month training in the harsh Siberian winter.

These boats made their way to India in early 1971. They were offloaded at Kolkata and towed along the Mumbai coast because there were no heavy cranes in Mumbai back then. This became the genesis of the Indian Naval command's idea that played a crucial role in Operation Trident. The Indian Navy realized the eight Osa-Is missile boats' could be towed to Karachi from Mumbai to overcome its short-range feature.

On December 3, 1971, the enemy Air Force launched an attack on six Indian airfields. In retaliation, the Indian Air Force (IAF) struck Pakistani airfields. Soon after, the Indian Army and Pakistani Army commenced ground battles in nearly every sector. The 1971 Indo-Pak War had begun officially. It was time for the Indian Navy's 'Killer Squadron' to join the war.

The same night, a group of Osa-I missile boats set sail from Mumbai harbour. Called INS Nipat, INS Nirghat and INS Veer, these boats were joined on December 4 by two Petya class Frigates - INS Katchall and INS Kiltan - to form the Trident team. After sailing westward and then northwards, the Osa-Is were towed successfully to Pakistan's naval bastion, the Karachi harbour, by night. The boats sailed in an arrowhead formation and altered course regularly to avoid enemy detection based on radar signals from INS Kiltan.

Interesting, the ship crews corresponded in Russian, making it difficult for enemy naval commanders to intercept the signals between the invading warships!

PNS Khaiber, a destroyer of the Pakistan Navy, was detected by the Rangout radar on INS Nirghat around 2243 hours. PNS Shah Jehan and the merchant vessel Venus Challenger, which was carrying ammunition for the Pakistani Army, were detected as well. The Osa-Is missile boats zeroed in on their targets with pinpoint accuracy and quickly released their Styx missiles. The Pakistani Navy was left in a state of utter shock. The bewildered naval force assumed that it was an aircraft fire from the Indian Air Force and engaged in vain the Styx missiles with their anti-craft guns.

In fact, before breaking apart and sinking, PNS Khyber sent out a mayday signal stating that it had been struck by an aircraft of the Indian Air Force. The Indian squadron had their sights set on the shore's petroleum storage facilities by this time. The three small missile boats stretched to their limits. They were virtually unprotected from air raids and released their final missiles (putting the entire Karachi harbour on fire) before turning around and returning full speed to Bombay. Interestingly, while the Indian ships were on their way back to safe waters, the Pakistan Air Force ended destroying one of its boats - PNS Zulfiqar - assuming that it was an Indian Navy boat!

The Indian Navy's 'Killer Squadron' received a heroes' welcome three days later. Operation Trident, which lasted for just 90 minutes, witnessed six missiles being fired that sank three front-line enemy vessels and destroyed the oil storage facilities in the Karachi harbour. No fatality on the Indian Navy's side was reported.

The Indian Navy, however, did not rest on the laurels following Operation Trident's resounding success. Four days later, it repeated the feat in Operation Python. Another three Pakistan Navy ships sank, and oil reserves were set on fire for the second time. These overwhelming victories severely restricted Pakistan's ability to engage Indian forces. The Indian Navy choked the enemy forces by destroying its oil, ammunition supplies and resupply routes.

Veterans and historians have often stated this to be a crucial turning point in the Indo-Pak War of 1971, which ended with the liberalization of Bangladesh. The world sat up and took note of the Indian Navy. So much so that Operation Trident was the first item in then US President Richard Nixon's morning brief by the CIA the next day.

Lt. Cdrs. BN Kavina, IJ Sharma and OP Mehta, commanders of the three Osa-Is missile boats, were honoured the Vir Chakra award for their outstanding bravery and precision execution of Operation Trident. Meanwhile, the man who led the 'Killer Squadron' Commodore BB Yadav was honoured with the Maha Vir Chakra.

Since then, December 4 is observed as Navy Day in India, a fitting homage to these brave soldiers who achieved one of the great sea-faring successes in Indian navy history.