HSL Completes Key Trials For Indian Navy's Diving Support Vessel 'Nistar'

Hindustan Shipyard Limited (HSL) has achieved a significant milestone by successfully completing diving system trials on its advanced Diving Support Vessel (DSV), Nistar, positioning India to become a leading exporter of advanced maritime vessels.

The Nistar, the first of two indigenously constructed vessels specifically designed for deep-sea diving and submarine rescue operations for the Indian Navy, recently concluded rigorous air diving system tests. These trials, involving unmanned and manned dives at varying depths, validated the vessel's reliability under challenging underwater conditions.

Additionally, successful Observation Remotely Operated Vehicle (OROV) trials demonstrated Nistar's capability for deep-ocean missions. Saturation diving trials, scheduled in the coming months, are expected to affirm its advanced operational credentials further.

At approximately 8,500 tons displacement and 120 metres in length, the Nistar meets rigorous international maritime standards, incorporating technologies typically associated with leading global naval forces.

It is equipped with a Dynamic Positioning System (DP-II), ensuring precise stability during critical underwater operations.

Specialised equipment onboard includes a six-person Decompression Chamber, a Submersible Decompression Chamber (SDC), also known as a Diving Bell-launched through a moon pool for enhanced diver safety-and a Self-Propelled Hyperbaric Lifeboat (SPHL).

Two sophisticated Remotely Operated Vehicles (ROVs), each capable of deep-water missions, and a heavy-duty marine crane featuring active heave compensation further augment Nistar's operational versatility. The vessel's capability to deploy a Deep Submergence Rescue Vehicle (DSRV), combined with a helideck facilitating rapid helicopter deployment, significantly strengthens the Indian Navy's submarine rescue and underwater response capabilities.

The Nistar project marks a notable turnaround for HSL, which, since the mid-1990s, had not received substantial naval orders requiring such high technical complexity, previously focusing instead on simpler commercial shipbuilding. Breaking this nearly three-decade hiatus, HSL successfully undertook and completed the highly sophisticated DSV project, effectively positioning itself and India within an elite group of shipyards globally capable of delivering advanced naval platforms.

"This achievement puts the spotlight on a substantial advancement for HSL, reflecting its evolution from simpler naval vessels to delivering highly complex and strategic maritime platforms," stated a senior official associated with the project. This transformative shift took place under the focused leadership of HSL's current Chairman and Managing Director, whose tenure has driven significant infrastructure upgrades and strategic technological collaborations, enabling this unprecedented capability leap.

Nistar strongly aligns with India's vision of defence self-reliance under Prime Minister Narendra Modi's "Atmanirbhar Bharat" initiative, actively involving over 120 MSME vendors to achieve more than 80% indigenous content. It also supports India's SAGAR (Security and Growth for All in the Region) policy, bolstering India's maritime security profile and regional diplomatic influence.

Industry analysts highlight that HSL's ongoing modernisation initiatives-including installing a 300-tonne Goliath crane, enhancing slipways, and proactively forming strategic technology partnerships-prepare the shipyard for future defence and commercial maritime projects.

They further note that the vessel's versatile design, proven performance, and high indigenous content significantly enhance India's competitive potential in exporting specialised maritime vessels, solidifying its reputation as a reliable maritime security partner in the Indo-Pacific region.

Aritra Banerjee is a Naval Author, and Defence & Security Columnist