Varunastra is an indigenous advanced heavyweight anti-submarine torpedo developed by the Naval Science and Technological Laboratory (NSTL), a DRDO laboratory, for the Indian Navy. Named after the mythological weapon of the Hindu god Varuna, the torpedo gives Indian surface combatants a modern, ship-launched anti-submarine strike capability with a very high level of indigenous content.[1]
Varunastra was developed by NSTL as part of India’s broader push to reduce dependence on imported torpedoes for anti-submarine warfare, building on decades of Indian underwater-weapons research. The programme achieved more than 95 percent indigenous content, an unusually high figure for a complex underwater weapon system that combines propulsion, guidance, sonar homing, and warhead technologies.[2]
The torpedo is approximately seven to eight metres long, weighs around 1,500 kg, and has a standard 533mm diameter compatible with international heavyweight torpedo launch systems. It is powered by an electric propulsion system drawing on multiple 250 kW Silver Oxide-Zinc batteries, giving it a top speed in excess of 40 knots (with some sources citing a maximum of up to 60 knots), a 250 kg conventional warhead, and the ability to operate at depths of up to 600 metres, covering the full depth envelope of most modern diesel-electric and nuclear submarines.[3]
Varunastra was inducted into the Indian Navy in 2016, with an initial order of 73 torpedoes followed by a second batch, bringing the total ordered to 136 units across two production batches. Bharat Dynamics Limited (BDL) manufactures the torpedo under licence from DRDO/NSTL; the first unit from a newer production batch was delivered by BDL’s Hyderabad facility to NSTL’s Visakhapatnam unit on 25 April 2026, reflecting continued serial production well beyond the original induction batches.[4]
On 20 March 2025, India’s Defence Acquisition Council cleared the Acceptance of Necessity for an additional batch of the ship-launched variant of the Varunastra torpedo, signalling continued Indian Navy demand for the weapon well after its initial 2016 induction and indicating confidence in its operational performance over nearly a decade of service.[5]
India has explored export opportunities for Varunastra, having offered versions of the torpedo to Vietnam as early as 2016. Bharat Dynamics Limited continues to list Varunastra on its official export portfolio as available for international sales, though formal export clearances and concluded deals for specific customers remain limited as of the latest reporting.
Varunastra closes a significant capability gap in India’s indigenous underwater-weapons inventory, providing surface ships with a credible, high-indigenous-content torpedo for anti-submarine warfare rather than relying solely on imported systems. Its continued production and procurement expansion through 2025-2026 reflect its established role as the Indian Navy’s standard heavyweight ship-launched torpedo.
| Type | Ship-Launched Heavyweight Anti-Submarine Torpedo |
| Manufacturer | DRDO (NSTL) / Bharat Dynamics Limited |
| Length | ~7-8 metres |
| Weight | ~1,500 kg |
| Diameter | 533 mm |
| Propulsion | Electric (Silver Oxide-Zinc batteries, 250 kW) |
| Speed | 40+ knots (up to 60 knots cited) |
| Max Depth | ~600 metres |
| Warhead | 250 kg |
| Entered Service | 2016 |
| Indigenous Content | 95%+ |