IN Brief:
- INS Nipun is the second Hindustan Shipyard-built Nistar-class diving support vessel commissioned into Indian Navy service.
- The ship supports saturation, air and heliox diving, remotely operated underwater systems, salvage, and Deep Submergence Rescue Vehicle operations.
- Basing Nipun under Western Naval Command complements sister ship INS Nistar in the east, giving the class a two-coast operating structure.
Hindustan Shipyard Limited has delivered the second vessel in India’s Nistar-class diving support programme into operational service, with INS Nipun commissioned at Naval Dockyard, Mumbai, on 31 August. The ship adds deep-sea diving, underwater intervention, salvage, remotely operated vehicle, and submarine-rescue support to the Indian Navy’s specialist fleet.
Nipun was delivered to the Navy on 30 July after outfitting and trials and has now been assigned to Western Naval Command. Sister ship INS Nistar entered service in July 2025 under Eastern Naval Command, giving the two-vessel class an operating presence on both Indian coasts.
The ships were designed and constructed by Hindustan Shipyard at Visakhapatnam and built to Indian Register of Shipping classification rules. At roughly 118 metres long, Nipun is a purpose-built support platform whose main engineering demands lie in diving, rescue, station-keeping, handling, power, life-support, and underwater intervention systems rather than the weapon and sensor architecture of a surface combatant.
Diving systems define the platform
The vessel supports saturation, air, and heliox diving, allowing teams to work at depth using different breathing-gas arrangements according to the task. Its specialist equipment includes a diving complex, side-diving stations, remotely operated underwater systems, medical and life-support facilities, and the interfaces needed to support India’s Deep Submergence Rescue Vehicle.
A DSRV can be deployed to reach a disabled submarine and recover trapped personnel, but the rescue vehicle itself is only one part of the system. A support ship must transport it, position accurately at sea, provide command and communications facilities, support launch and recovery, sustain specialist crews, and remain stable while underwater operations are under way.
Dynamic positioning is therefore central to the class. Diving and rescue tasks may require the ship to hold a tightly controlled position for extended periods despite wind, current, and sea state. Propulsion, navigation sensors, automation, and vessel-control systems have to work together to maintain that position without relying solely on anchoring arrangements.
The same station-keeping capability supports ROV and salvage operations. Remotely operated vehicles can inspect underwater structures, monitor diving activity, locate objects, and assist intervention at depths or in conditions where sending divers would be difficult or unsafe. Their effectiveness depends on launch-and-recovery equipment, power and data connections, control stations, and the ability of the mother ship to maintain a predictable position above the work site.
Nipun is consequently an integration-heavy vessel despite its limited combat role. Pressure systems, breathing-gas management, decompression facilities, medical support, ROV handling, communications, navigation, dynamic positioning, propulsion, electrical generation, auxiliary services, and rescue-system interfaces all have to operate independently and as part of one safety-critical package.
Trials shift into through-life readiness
The Navy says Nipun’s diving systems were proved for role-worthiness during sea trials before delivery. Acceptance of a specialist support ship depends on that mission equipment working under realistic operating conditions, because satisfactory propulsion and basic ship handling alone do not establish that saturation diving or underwater rescue systems are ready for service.
Commissioning therefore closes one engineering phase rather than the programme as a whole. The vessel now enters a longer period in which reliability, crew proficiency, maintenance, certification, spares, and repeated training will determine how much rescue capability is actually available at short notice.
Submarine rescue places unusually severe demands on readiness because the requirement is infrequent but time-critical. Equipment that spends long periods waiting for an emergency still has to be maintained, exercised, and certified, while crews need enough routine training to remain current across diving, ROV, launch-and-recovery, medical, and rescue procedures.
The class also forms part of India’s wider naval industrial policy. The Ministry of Defence reported nearly 75% indigenous content when Nipun was delivered, while the programme has involved a network of domestic suppliers around Hindustan Shipyard. The percentage provides a broad measure of localisation, although the more useful long-term indicator will be the degree to which Indian organisations can maintain, repair, modify, and support the specialist systems throughout the vessels’ service lives.
That distinction is important for a ship type produced in small numbers. Diving support vessels do not offer the economies of a large serial warship programme, so retaining engineering knowledge, supplier capability, documentation, test equipment, and qualified personnel becomes a significant part of through-life support.
Hindustan Shipyard also gains experience in integrating systems that sit outside conventional ship construction. Pressure chambers, gas-management equipment, diving control, ROV handling, rescue interfaces, and high-reliability positioning systems create certification and safety requirements that differ from those on a general-purpose auxiliary vessel.
The two-coast basing arrangement should reduce the distance one vessel has to cover when responding to an incident, although actual response time will depend on location, readiness state, weather, crew availability, and the status of the associated rescue systems. The Navy has also positioned the class as a capability that could assist partner countries during submarine emergencies.
That regional role makes interoperability and exercising important. Rescue systems are of limited use if interfaces, communications, procedures, or support arrangements have not been tested before an emergency, particularly when a response involves another navy’s submarine design and personnel.
Nipun has now completed construction, acceptance, delivery, and commissioning. The industrial measure of the class will increasingly shift away from hull completion and towards operational availability: whether both vessels can maintain their diving complexes, ROVs, dynamic-positioning equipment, rescue interfaces, and trained crews at the readiness required for an underwater emergency.
