You are seeing the Type 53-65 533mm Torpedo that is carried by Indian Navy’s INS Chakra and Kilo Class submarines !
This Russian torpedo is considered very threatening even by the United States Navy. This is so because Type 53-65 does not respond to usual torpedo counter-measures employed by ships. Normal counter-measures are decoys that use noise to divert the homing torpedoes. But Type 53-65 uses sensors that instead detect the churn made by moving ships. Then it follows the churn in an S-pattern between the wakes unless it is just 11.8 m from impact.
Type 53-65 is armed with a 307kg warhead and features an updated homing system, which, in addition to the traditional passive wake homing, features a phased array active sonar and an improved wire guidance system.
When Indian Navy’s Conventional Submarine ‘Annihilated’ US Navy’s Nuclear Submarine With Its 533mm torpedo :
In the 1971 war for liberation of Bangladesh, US Navy’s 7th fleet had shown hostile posturing towards India while stationed in Bay of Bengal. But as an officer from submarine arm of Vishakhapatnam based Eastern Naval Command related, Indian Navy had a sweet revenge in the high profile Malabar exercise between navies of USA, Indian and Japan.
The exercise featured a simulated battle to hunt and destroy each other’s submarines. Locked in this match were two prowlers – INS Sindhudhvaj, an 877EKM class conventional submarine and USS City of Corpus Christie (SSN-705), a Los Angeles Class nuclear powered attack submarine. The crew of both the submarines were asked to hunt the other down in general area of Bay of Bengal.
They subsequently dived. Hours later as they still searched in water, the Americans were informed the game was already over. SSN-705 had been marked, tailed and suitably annihilated by the 53-65 533mm torpedo of 877EKM class. The much vaunted Los Angeles Class had been identified by the newly installed SONAR of Kilo-class with its sound navigation and ranging. In simple terms, hydraulic effects and noise under water of the nuclear submarine had given itself away to Indian Navy’s conventional submarine.
This is precisely why Western Navies have given the Kilo-Class submarines the nickname of ‘Blackholes under water’.