The Arihant-class nuclear-powered submarines represent a cornerstone of India's strategic deterrence, with the fourth vessel, designated S4*, poised to join the fleet as INS Arisudan. Launched by Defence Minister Rajnath Singh on 16 October 2025, this submarine embodies the Sanskrit theme of 'destroyer of enemies' shared by its predecessors: INS Arihant, INS Arighaat, and INS Aridhaman.

The naming process for INS Arisudan follows established naval protocol, beginning with a proposal from the Indian Navy's ship-naming committee.

This recommendation advances to the Defence Ministry for clearance before final approval by the President of India. Commissioning remains targeted for 2027, bolstering India's sea-based nuclear triad amid ongoing regional tensions.

INS Aridhaman, the third in the class, advances towards induction in early 2026 following intensive sea trials. Launched in November 2021 at Visakhapatnam's Ship Building Centre, it features an upgraded Compact Light Water Reactor for enhanced stealth and endurance. Larger by about 1,000 tonnes than INS Arihant, it accommodates eight vertical launch tubes for advanced missiles.

Unlike the lead boat INS Arihant, limited to K-15 Sagarika missiles with a 750 km range, subsequent Arihant-class vessels integrate the K-4 submarine-launched ballistic missile boasting 3,500 km reach. DRDO and the Strategic Forces Command continue trials, achieving high accuracy in recent Bay of Bengal tests from INS Arighaat. These unlimited-range capabilities enable deterrent patrols across the Indo-Pacific.

India's no-first-use nuclear doctrine underscores the submarines' role in second-strike assurance, contrasting Pakistan's first-use policy while aligning with China's stance. The subsurface leg proves most survivable within the nuclear triad, evading pre-emptive detection.

Parallel advancements include the P77 project, greenlit by the Narendra Modi government on 9 October 2024 for indigenous nuclear-powered attack submarines (SSNs). Valued at ₹40,000 crore, it targets two initial boats at Visakhapatnam with Larsen & Toubro involvement, eyeing 95% indigenous content and first delivery by 2036-37.

Russia supports this expansion via a 2019 lease for an Akula-class SSN (INS Chakra III), delayed to 2028 at a $3.3 billion cost. Moscow has offered a second blue-water Akula ahead of President Vladimir Putin's 5 December 2025 India visit, potentially enhancing interim capabilities.

Indian Navy naming conventions maintain thematic consistency across classes. SSBNs evoke 'Arihant' (enemy destroyer), diesel-electric Kalvari-class honour decommissioned Russian Foxtrots, destroyers bear city names like INS Kolkata and INS Surat, while frigates draw from rivers and mountains such as Ganga and Shivalik classes. The class name derives from the lead ship, reinforcing naval heritage.

​Based On Hindustan Times Report