Overview
- Defense sources report INS Aridhaman (S4) has completed deep-sea trials and could enter service as early as April or May 2026.
- The submarine displaces about 7,000 tonnes and adds eight vertical launch tubes, enabling up to 24 K-15 or eight K-4 ballistic missiles, with provisions for the longer-range K-5.
- Propulsion comes from an 83 MW compact light water reactor with a reduced acoustic signature, complemented by a seven-blade propeller, indigenous USHUS and Panchendriya sonars, and anechoic tiles.
- Once operational, three SSBNs under Strategic Forces Command would support a patrol rotation that moves India toward Continuous At-Sea Deterrence and a more credible second-strike posture.
- The boat is slated to operate from the hardened Project Varsha base near Visakhapatnam, as India also pursues the Akula-class Chakra III by 2027–28 and negotiates six Project-75(I) diesel-electric submarines with Germany.