Three Indigenous Naval Classes for Combat, Survey and Coastal Defence
India’s maritime strength depends on a balanced fleet protecting national interests across the full spectrum of naval operations. The Nilgiri, Sandhayak and Arnala classes represent three vital pillars of this capability. Recently commissioned INS Dunagiri, INS Sanshodhak and INS Agray demonstrate the steady expansion of these indigenous warship classes. INS Mahendragiri further strengthens this capability. Built with high indigenous content, these platforms embody Aatmanirbhar Bharat and strengthen India’s defence manufacturing ecosystem. Together, they enhance maritime security, support the Blue Economy and reinforce India’s position as a leading maritime power.
India’s Layered Naval Capability
The Indian Navy is a primary security provider in the Indian Ocean Region. It safeguards a coastline of about 11,098 kilometres, an Exclusive Economic Zone of nearly 2.4 million square kilometres, and sea lanes carrying close to 90 per cent of India’s trade by volume. Achieving this requires a balanced fleet, with each class of warship contributing to a distinct layer of maritime security. In India, four new-generation indigenous naval platforms inducted in just one month now bring this layered approach to life.
The ability to deter and fight on the ocean surface sits at the front of this structure. The latest in this segment are Nilgiri-class stealth frigates which are built under Project 17A for high-intensity operations. Their reduced radar, thermal and acoustic signatures improve survivability in combat.
Maritime power also depends on a deep understanding of the seas. The Sandhayak-class Survey Vessel (Large) ships strengthen India’s hydrographic capability. They map the seabed, gather ocean data and produce accurate nautical charts for safe navigation. This work supports naval operations, maritime trade and the Blue Economy, and it reinforces India’s standing as a trusted hydrographic partner across the Indian Ocean Region.
Closer to the coastline, anti-submarine warfare forms the next layer of defence. The Arnala-class Anti-Submarine Warfare Shallow Watercrafts are designed to detect and neutralise submarines in littoral waters. Alongside their core roles, all three classes can take on humanitarian assistance, disaster relief and search and rescue missions.
Together they mark the success of India’s indigenous shipbuilding programmes. Their move into serial production strengthens maritime security, advances Aatmanirbhar Bharat and shows India’s growing ability to design and build its own warships.
Did You Know?On 21 June 2026, three indigenously designed and built platforms were commissioned together at Kolkata: INS Dunagiri, a Nilgiri-class stealth frigate; INS Sanshodhak, a Sandhayak-class survey vessel (large); and INS Agray, an Arnala-class anti-submarine warfare shallow water craft. All three ships were designed by Navy’s own Warship Design Bureau and manufactured by the Garden Reach Shipbuilders and Engineers Limited (GRSE), Kolkata, a defence public sector undertaking. On 11 July 2026, the sixth indigenously designed and built Nilgiri-class stealth frigate INS Mahendragiri was commissioned at Visakhapatnam |
Stealth Frigates: The Cutting Edge of Surface Power
Stealth frigates form the backbone of the Indian Navy’s surface combat capability. They protect aircraft carriers, secure vital sea lanes and project power across distant waters. Designed for modern naval warfare, they integrate advanced weapons, sensors, and aviation facilities while optimizing radar, infrared (thermal), and acoustic signatures for enhanced stealth. This makes them difficult to detect while enabling both offensive and defensive operations.