Indian Navy to Commission Second Indigenous Diving Support Vessel Nipun in Mumbai on August 31
Mumbai / New Delhi: The Indian Navy will commission Nipun, the second vessel in the indigenous Nistar-class Diving Support Vessel programme, at the Naval Dockyard in Mumbai on 31 August 2026, completing a two-ship capability intended for deep-sea diving, underwater intervention and submarine rescue from both coasts.
Built by Hindustan Shipyard Limited (HSL) in Visakhapatnam, the specialised ship was delivered to the Navy on 30 July 2026 after outfitting and trials. Its induction will give the Western Naval Command a dedicated diving support vessel similar to sister ship INS Nistar, which was commissioned at Visakhapatnam in July 2025 and is based with the Eastern Naval Command.
The name Nipun is Sanskrit for someone who is adept, capable and well-versed in a particular discipline — a fitting description for a platform designed for tasks that require rare and highly specialised maritime capability.
A gap that the Navy had to bridge
For years, India’s dedicated diving support and submarine rescue requirements were met in a less permanent way, often through commercially leased vessels such as SCI Sabarmati, which served as temporary motherships for Deep Submergence Rescue Vessels (DSRVs). An earlier Indian ship also named Nistar, acquired during the Soviet era, had been phased out decades ago. As the submarine fleet expanded, that absence became more consequential, particularly because the window for rescuing a disabled submarine can be extremely short.
The urgency of such preparedness was reinforced globally by incidents such as the 2021 loss of Indonesia’s KRI Nanggala, which highlighted how quickly a rescue opportunity can disappear once a submarine is in distress. Against that backdrop, India moved to create a permanent indigenous rescue and diving platform rather than depend on ad hoc arrangements.
The contract for two indigenous Diving Support Vessels was signed with HSL on 20 September 2018 for about ₹2,393 crore. Keels were laid for Nistar in December 2019 and for Nipun in March 2020. The two ships were launched together on 22 September 2022. Their delivery schedule slipped, partly because of the Covid-19 disruption, but the first ship was handed over on 8 July 2025 and commissioned on 18 July 2025, with the second following a year later.
Nistar has already been put to operational use. In September 2025, she took part in Exercise Pacific Reach off Singapore, where DSRV Tiger X carried out mating drills with foreign submarines. That deployment offered a public demonstration of the rescue architecture that Nipun will now replicate on the western seaboard.
What the ship is designed to do
Official descriptions make clear that Nipun is not a general-purpose auxiliary fitted with diving gear, but a vessel purpose-built for underwater operations. Its main tasks include saturation diving to about 300 metres, air and mixed-gas diving from a side diving stage down to around 75 metres, and submarine rescue as the mothership for a DSRV that can mate with a distressed submarine and evacuate its crew.
The ship is also meant for salvage and intervention work using remotely operated vehicles (ROVs), with reported capability down to about 1,000 metres for monitoring and underwater tasks. In addition, it carries medical support systems, including hyperbaric and hospital facilities needed after deep dives or a rescue operation.
The Ministry of Defence says the vessel has modern navigation and platform-management systems as well as precise station-keeping ability, which are crucial when a ship must remain steady over a working site while divers, a diving bell or a DSRV are operating below. Dynamic positioning of DP-2 class is part of the design.
Class-wide equipment described in official and technical accounts includes a moon-pool-launched submersible decompression chamber, or diving bell, a six-person decompression chamber, a self-propelled hyperbaric lifeboat, observation-class ROVs, side-scan sonar, a roughly 15-tonne-class subsea crane and a flight deck for helicopter operations. The ships also carry limited self-defence armament, including 30 mm AK-630 close-in weapons.
Saturation diving is the capability that most clearly sets a true DSV apart from a simple diving tender. Divers live in pressurised chambers aboard the ship, transfer under pressure to the work site and decompress only after completing a multi-day task. This is the method used for work on pipelines, wrecks, hull fittings and seabed infrastructure at depths where repeated descent and ascent would be inefficient or unsafe.
Size, endurance and the varying figures
Official Navy language on the lead ship describes a vessel about 118 metres long with a displacement of nearly 10,000 tonnes. Other briefings on Nipun have used a figure of over 8,560 tonnes. Independent technical summaries commonly list dimensions of about 118.4 metres in length and 22.8 to 23 metres in beam, diesel propulsion, a cruising speed of around 14 knots, endurance of about 60 days and accommodation for roughly 25 officers and 225 sailors. The displacement figures should be treated as approximate until the Navy publishes a single official table for Nipun.
What remains consistent across the available descriptions is the scale of the vessel. It is large enough to carry saturation systems, a DSRV, ROVs, medical spaces and stores for long deployments, while still remaining a ship capable of staying on station for the kind of work it is designed to perform.
Why the DSRV role is central
The most important function of the class is submarine rescue. India has acquired two deep-submergence rescue systems so that a response can be mounted from either coast. A DSRV is a small pressure-resistant craft launched from a surface mothership. It locates a disabled submarine, mates with the rescue hatch and transfers crew to safety. But the system works only if the mothership can hold position, handle the vehicle, and provide the medical and hyperbaric support needed after a rescue.
With Nistar covering the east, where much of the nuclear submarine infrastructure is concentrated, Nipun gives the Western Naval Command a matching host platform. Together, the two ships reduce the risk that a refit, maintenance cycle or crisis on one coast could leave the Navy without a ready rescue vessel.
The same ship can also support salvage, wreck survey, harbour-clearance diving and non-combatant or search-and-rescue missions. Those secondary roles may be more common in peacetime, but the rescue mission remains the design driver for the class.
Indigenous content and HSL’s role
The Navy and the Ministry of Defence say indigenous content on Nipun is nearly 75 per cent, while some industry accounts on the class put the figure above 80 per cent. The ships were designed and built to Indian Register of Shipping classification rules. HSL, a Miniratna defence PSU with a long association with submarine work, drew on a broad vendor base, with reports around the delivery citing about 120 micro, small and medium enterprises.
Acceptance documents at delivery were signed by Rear Admiral Arvind Rawal, Chief Staff Officer (Technical), Western Naval Command, and Rear Admiral Chandrasekharan Raghuram (Retd.), Chairman and Managing Director of HSL.
Officials have presented the programme as part of Aatmanirbhar Bharat and Make in India, not just because the hull was built in India but because the more difficult task was integrating saturation diving systems, dynamic positioning, medical hyperbaric plant and DSRV handling on an Indian-built warship. That does not mean every subsystem is Indian-origin; specialised diving and rescue equipment remains a narrow global market. The broader policy point, however, is that the platform is no longer a foreign lease or a one-off import.
The class should not be confused with the smaller Diving Support Craft programme, which consists of catamaran hulls built by Titagarh Rail Systems for coastal diving tasks. Those craft are meant to complement the large DSVs rather than replace them.
Why the timing matters
India’s submarine fleet is expanding, with conventional boats on both coasts and nuclear boats centred on the east, as new Kalvari-class submarines and indigenous nuclear programmes mature. Each additional submarine increases the operational need for rescue cover. The DSV fleet also gives India a useful maritime diplomacy tool: Nistar’s participation in Exercise Pacific Reach showed that the Navy can contribute a rescue asset in a multinational environment, not only support its own submarines.
There is also an industrial lesson in the programme. Complex auxiliaries are often more difficult to design and integrate than they first appear. A destroyer’s combat system is demanding; a DSV’s combination of station-keeping, life support under pressure and subsea handling is demanding in a different way. The fact that HSL has delivered a second ship a year after the first suggests the yard has moved beyond the learning curve of the lead vessel, even if the original 36-month contractual schedule was not met.
What commissioning will mean
When Nipun is commissioned on 31 August, it will move from builder’s and acceptance trials into active service. That does not mean every diving regime will be certified immediately. Saturation systems, DSRV mating and medical pathways normally continue to be refined under naval diving and submarine-rescue units after the commissioning pennant is hoisted.
The Navy says the ship will augment rescue capability and strengthen specialised missions across India’s maritime areas of interest. Once both Nistar-class ships are in commission, India will own two purpose-built indigenous motherships instead of relying on a single new hull alongside leased commercial tonnage. In practical terms, that is the real significance of the Mumbai ceremony: a second specialist platform in a niche where readiness can determine whether a submarine accident ends in rescue or recovery.
