'Nipun' Joins the Fleet: India's Second Indigenous Diving Support Vessel Delivered

Hindustan Shipyard Limited (HSL) has delivered Nipun, the second indigenously built Diving Support Vessel (DSV) of the Nistar class, to the Indian Navy at Visakhapatnam. The handover — reported at the end of July and formally accepted in early August 2026 — quietly extends one of the more specialised and technically demanding capabilities in India's naval inventory: deep-sea diving and submarine rescue.

A ship built to go down, and bring people back up

A diving support vessel is not a warship in the conventional sense. Its job is to serve as a floating base for saturation diving and, critically, as the mother ship for the Navy's Deep Submergence Rescue Vehicle (DSRV) — the small submersible that can mate with a stricken, bottomed submarine and evacuate its crew. Few navies operate this capability, and until recently India had to rely on foreign assistance for undersea rescue.

Nipun is a large platform — roughly 118 metres long and displacing close to 10,000 tonnes — engineered to hold a precise position over a dive site in open water. That is harder than it sounds: to keep divers and a rescue vehicle safe, the ship must counteract wind, current and swell without anchoring, using a dynamic positioning system that continuously trims its thrusters against the sea.

Saturation diving, explained

The vessel's headline capability is saturation diving to around 300 metres. In saturation diving, divers live for days or weeks inside a pressurised chamber system aboard the ship, their bodies "saturated" with breathing gas at the pressure of their working depth. They are shuttled to the seabed in a closed diving bell and returned to the chamber between shifts, decompressing only once at the end of the whole operation rather than after every dive. It is the only practical way to do sustained heavy work at those depths — on sunken hulls, pipelines or salvage — and it demands a tightly integrated suite of chambers, gas handling, life support and remotely operated vehicles (ROVs), all of which Nipun carries.

Made in India, mostly

Nipun and its sister ship were built to a high level of indigenisation — around 75% indigenous content, according to the Navy — a meaningful figure for a platform this specialised, where diving and life-support systems have historically been imported. The vessels were designed and constructed by Hindustan Shipyard Limited, the Visakhapatnam-based defence public-sector shipbuilder, and the programme has helped build a domestic supplier base for undersea engineering that did not previously exist at scale.

The Nistar class

Nipun is the second of two Nistar-class DSVs. The lead ship, INS Nistar, was commissioned into the Navy in July 2025, reviving a storied name — the original Nistar supported the salvage of the submarine INS Sindhurakshak. With Nipun now delivered, the Navy gains a second hull, allowing continuous coverage: one vessel can be on station or on rescue standby while the other refits or repositions, on either the eastern or western seaboard.

The delivery also dovetails with a broader push in indigenous undersea capability. Around the same window, the Navy launched DSC A24, the fifth and final craft of a separate Diving Support Craft project being built at Titagarh Rail Systems in Kolkata — smaller, harbour-and-coastal diving platforms that complement the ocean-going DSVs.

Why it matters

Submarine rescue is one of those capabilities a navy hopes never to use but cannot afford to lack. As India's submarine fleet grows — conventional boats today, and a widening undersea presence in the Indian Ocean — the ability to reach and recover a distressed crew independently, without waiting for an allied asset to fly in, is a strategic as much as a humanitarian asset. Nipun's delivery makes that capability more resilient, and it does so with a ship that is largely designed and built at home.

For India's deep-tech story, the vessel is a reminder that "frontier technology" is not only chips and rockets. Saturation diving systems, dynamic positioning, integrated ROV operations and the engineering to keep humans alive under 30 atmospheres of pressure are hard problems — and India can now build the platform that solves them.

Sources

• Naval Today — "Hindustan Shipyard delivers second Diving Support Vessel to Indian Navy": https://www.navaltoday.com/2026/08/03/hindustan-shipyard-delivers-second-diving-support-vessel-to-indian-navy
• The Defense Post — "Indian Navy Accepts Second Nistar Diving Support Ship From HSL": https://thedefensepost.com/2026/08/04/india-nistar-diving-support-ship/
• Insights on India — "Nipun: India's Indigenous Diving Support Vessel": https://www.insightsonindia.com/2026/07/31/nipun-indias-indigenous-diving-support-vessel-dsv/
• Wikipedia — "Nistar-class diving support vessel": https://en.wikipedia.org/wiki/Nistar-class_diving_support_vessel