INS Chamak, an Indian Navy missile boat, launching an SS-N-2 Styx missile

Even as various national leaders congratulate the Indian Navy on Navy Day, which falls on December 4, the real significance of the anniversary has often been undervalued.

Navy Day marks the success of Operation Trident, the daring attack by Indian Navy missile boats on the Pakistani port city of Karachi in the 1971 Bangladesh Liberation War. The missile strikes by three Indian Navy missile boats of the Soviet-built Osa class—the Nipat, Nirghat and Veer—on Karachi harbour saw the sinking of three vessels, including two Pakistani warships.

Operation Trident and Operation Python, another missile boat attack on Karachi on December 8, saw the Indian Navy raise the bar on ingenuity and courage by using small ships in offensive operations and made naval planners all over the world sit up and take notice.

The attacks were carried out by the Soviet-built SS-N-2 'Styx' anti-ship missile, which had been used by the Egyptian Navy to sink an Israeli warship, the Eilat, in 1967.

In his seminal book Transition to Triumph: Indian Navy 1965-1975, retired vice admiral G.M. Hiranandani recalls Pakistan was offered six Osa class missile boats by the Soviet Union in 1968, but declined them. The Pakistani assessment was that the Osa class missile boats were useful only for harbour defence and not worthwhile for offensive operations.

The Osa class missile boats, while being small in size, had limited range, radar detection capabilities and minimal defences against air attack. The Indian Navy attempted to overcome these limitations by 1) towing the three missile boats from what was then Bombay to off the coast of Gujarat and
2) launching the attack by night to minimise the risk of air attack. Operation Trident and Operation Python also saw the destruction of oil installations in Karachi by missiles launched from sea.

The missile attack on the Israeli warship in 1967 and the Karachi attacks led to a surge in development by navies of countermeasures to defeat systems like the SS-N-2 Styx using methods such as radar jamming.

In the 1973 Yom Kippur War, Israel and Syria engaged in a naval battle between missile boats in what would become known as the Battle of Latakia. The Israeli Navy managed to neutralise several Styx missiles using countermeasures, before launching its own, shorter-range, missiles to destroy the Syrian missile boats.