How Indian Navy's recently inducted warships support survey and combat

India has inducted four indigenous warships within a month, bolstering the navy's layered maritime capability across surface combat, hydrographic surveys and coastal anti-submarine warfare (ASW) crafts, while also boosting the country's self-reliance in defence manufacturing.

The four platforms — INS Dunagiri, INS Sanshodhak, INS Agray and INS Mahendragiri — belong to three different indigenous warship classes that together form a multi-layered maritime defence architecture.

These ships enhance maritime security, support the blue economy and push India's position as a leading maritime power in the Indian Ocean region. 

The Navy safeguards an approximately 11,098 kilometres of coastline, an exclusive economic zone of nearly 2.4 million sq km, and sea lanes that carry around 90 per cent of the country's trade by volume. To secure these routes, the Navy relies on different classes of vessels, each designed for a specific operational role.

The Nilgiri-class stealth frigates, built under Project 17A, represent the Indian Navy's primary surface combat capability. It is designed for anti-air, anti-surface and anti-submarine warfare, featuring reduced radar, thermal and acoustic signatures to improve survivability during combat operations.

Each frigate measures around 149 metres, displaces about 6,670 tonnes and can attain a maximum speed of 28 knots using a combined diesel or gas propulsion system. They are equipped with BrahMos supersonic missiles, medium-range air defence missiles, advanced radar, hull-mounted sonar and helicopters for multi-mission operations.

The Nilgiri-class currently comprises INS Nilgiri, INS Himgiri, INS Taragiri, INS Udaygiri, INS Dunagiri, INS Mahendragiri, while INS Vindhyagiri is under construction. Of the seven frigates, Mazagon Dock Shipbuilders Limited has built four, while Garden Reach Shipbuilders and Engineers has built the remaining three.

INS Dunagiri, the fifth ship of the class, was commissioned recently, followed by INS Mahendragiri, the sixth vessel, which was commissioned at Visakhapatnam on July 11, 2026.

While combat ships protect India's maritime interests, the Sandhayak-class Survey Vessel (Large) (SVL) supports naval operations through hydrographic surveys. These vessels map the seabed, collect oceanographic data and prepare accurate nautical charts that are essential for safe navigation, maritime trade and coastal infrastructure development.

The Indian Navy is inducting the indigenous SSVL built by Garden Reach Shipbuilders and Engineers, including INS Sandhayak, INS Nirdeshak, INS Ikshak and INS Sanshodhak. INS Sanshodhak was recently commissioned as the fourth and final ship of the class.

These vessels are about 110 metres long with a displacement of roughly 3,400 tonnes, and a top speed of over 18 knots with an operational range of 6,500 nautical miles. The ships are equipped with multi-beam echo sounders, side-scan sonar and autonomous underwater vehicles capable of detailed seabed mapping. Besides hydrographic surveys, they can also operate helicopters and function as hospital ships during emergency situations in the region.

India's hydrographers surveyed 89,000 square kilometres and produced 96 charts between 2019 and 2024, assisting friendly nations, according to a media statement released by the press information bureau.

The third class in the category is the Arnala-class Anti-Submarine Warfare Shallow Water Craft, specifically designed to detect and neutralise submarines operating in shallow coastal waters. Apart from ASW roles, these ships are also capable of undertaking humanitarian assistance, disaster relief and search-and-rescue operations.

The eight-ship class, built by Garden Reach Shipbuilders and Engineers in partnership with L&T Shipbuilding comprises Arnala, Androth, Anjadip, Amini, Abhay, Agray, Akshay and Ajay.

INS Agray was recently commissioned as the fourth ship of the class, while a parallel Mahe-class is under construction at Cochin Shipyard, taking the planned fleet strength to 16 ASW vessels.

The Arnala-class measures around 77.6 metres in length and displaces about 900 tonnes. The craft uses waterjet propulsion, which provides greater manoeuvrability in coastal waters compared to conventional propellers and can achieve speeds of around 25 knots.

They are equipped with lightweight torpedoes, anti-submarine rockets, shallow-water sonar and an integrated combat management system that links onboard sensors with weapon systems for rapid threat detection and engagement.

The three warship classes are designed by the navy's warship design bureau and built in Indian shipyards with 75–80 per cent indigenous content.