India's Grey Counter: How New Delhi Is Fighting China's Invisible War In The Indian Ocean

Data shows Chinese vessel conducting repeated survey missions between 2024 and 2025 across strategic waters near Taiwan, Guam, and, critically, through the Indian Ocean

There is a version of a contest that occurs with no shots fired, no diplomatic communiqués, and no headlines. It unfolds in the deep waters of the Ninety East Ridge, in the quiet rotations of a research vessel near Sri Lanka, in the gap between two radar pings as a ship switches off its transponder south of the Malabar coast. It is the contest that Beijing has been winning, largely undisturbed, in India’s maritime backyard. Until New Delhi, slowly but with growing urgency, began to push back.

That reckoning is now underway. India’s response to China’s grey-zone maritime strategy, in times of neither war nor peace, a deliberate campaign of intelligence-gathering, infrastructure seeding, and presence-by-stealth, is taking shape across multiple fronts. From the deployment of underwater sensor networks to the fast-tracking of the procurement of autonomous maritime systems, New Delhi is building the architecture of a maritime surveillance state. The question is not whether India is responding. It is whether it is responding fast enough and whether it will be adequate.

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The Architecture of Ambiguity

China has mastered the grammar of ambiguity at sea. The research vessel Dong Fang Hong 3, operated by the Ocean University of China, is emblematic of the same. Ship-tracking data shows the vessel conducting repeated survey missions between 2024 and 2025 across strategic waters near Taiwan, Guam, and, critically, through the Indian Ocean, including routes approaching Sri Lanka, Indonesia, and the vital Malacca Strait. Chinese authorities describe these missions as climate science and seabed analysis. Naval experts are less credulous. Deep-sea mapping yields the kind of data that allows submarines to navigate covertly, evade detection, and operate at maximum efficiency. The science is, for the most part, real, but so is its military utility, which is what China is after.

And the Dong Fang Hong 3 is not alone. China’s ocean-mapping programme has documented dozens of research vessels and hundreds of seabed sensors sweeping the Pacific, Indian, and Arctic oceans in what amounts to a sustained subsurface intelligence effort. The Ridge figures prominently in that survey record, a 5,000-kilometre underwater mountain chain running through the central Indian Ocean whose topography offers natural navigational cover for submarine transit towards the Andaman Sea and India’s eastern seaboard.

Since 2020, the PLAN has roughly doubled the number of submarines it rotates through the Indian Ocean Region. Yuan-class diesel-electric boats and Jin-class ballistic missile submarines have been tracked operating within range of Indian waters. The surface picture is equally telling: Chinese vessels, research ships, survey platforms, and merchant traffic with state connections have repeatedly switched off their AIS transponders while transiting sensitive areas of the IOR, creating deliberate gaps in any tracking record that a single nation, acting alone, could hope to assemble.

The Encirclement Design

At sea, China’s strategy is inseparable from its broader effort to reshape the strategic geography around India. Beijing has spent years cultivating a network of economic and military relationships across South Asia and the Indian Ocean littoral to try and create an anti-India arc. The China-Pakistan Economic Corridor, whose announced value has risen to approximately 62 billion US dollars, provides China a direct route from Xinjiang to the Arabian Sea via Gwadar, easing the Malacca Strait chokepoint while entrenching a permanent strategic presence on India’s western flank. Colombo, Hambantota, and other Indian Ocean ports carrying the hallmarks of Belt and Road investment are potential dual-use strongpoints from which Chinese naval logistics could be supported in a crisis. The convening of the China-Indian Ocean Forum, through which Beijing has cultivated diplomatic traction among littoral states, adds a political dimension to what is otherwise a military-intelligence campaign. China is using the Indian Ocean as a strategic laboratory, experimenting with instruments of influence unavailable elsewhere.

What makes this particularly challenging for India is that the campaign is designed to operate below the threshold of a conventional response. Mapping a seabed is not an act of war. Berthing a vessel at a friendly port is not an act of war. Going dark on an AIS transponder is not, in itself, a provocation. The cumulative effect, however, is a systematic erosion of India’s situational awareness in the waters it considers central to its security.

India’s Surveillance Architecture Taking Shape

New Delhi’s most concrete answer has been the Deep Ocean Watch initiative, developed jointly with the DRDO. The system is being built around a layered detection architecture: fixed passive and active sonar arrays anchored in the Ninety East Ridge corridor and the Bay of Bengal, towed array sonars aboard P-8I Poseidon patrol aircraft and Kolkata-class destroyers, and Magnetic Anomaly Detectors combined with superconducting quantum interference devices capable of registering the electromagnetic signature of a submarine hull at depth.

The model is the US-Japan Fish Hook network in the Pacific, which fuses fixed seabed sensors with airborne and shipborne assets to monitor key transit chokepoints, and which India has explicitly studied as it constructs its own version across the Andaman and Nicobar landscape.

The IFC-IOR in Gurugram, established in 2018 and now receiving data from more than 40 partner navies and coast guards, provides the nerve centre through which much of this information flows. Washington, Tokyo, and Canberra have all signalled willingness to integrate submarine movement data into India’s picture under the IPMDA framework, extending New Delhi’s reach well beyond what its own sensors can cover.

In addition, NavIC, India’s regional satellite navigation system, adds a vessel-tracking layer across the broader IOR, complicating the ability of foreign vessels to operate undetected across India’s extended maritime approaches.

On the hardware side, the MoD signed contracts with Kalyani Strategic Systems in November 2025 for more than Rs 250 crore in underwater systems, with a delivery deadline of November 2026. Kalyani has been supplying autonomous underwater vehicles to the Navy for several years; this contract, awarded outside the standard defence acquisition cycle under fast-track norms, shows the degree of urgency now attached to subsurface capability. That the group accepted a compressed timeline is itself an indication of how quickly its industry base has matured.

Project 75I and the Undersea Deterrent

In August 2025, the Cabinet Committee on Security approved negotiations with Mazagon Dock Shipbuilders and Germany’s ThyssenKrupp Marine Systems for six advanced diesel-electric submarines under Project 75I, at a projected cost of roughly Rs 99,000 crore. What is special about them? Well, these boats feature an air-independent propulsion. A conventional diesel-electric submarine must come to periscope depth every 48 hours or so to run its snorkel and recharge its battery bank, a predictable, detectable routine that represents the platform’s greatest operational liability. AIP, driven by hydrogen fuel cells, removes that constraint, allowing a boat to remain submerged for up to three weeks. In the Indian Ocean, where Chinese surveillance assets above and below the waterline are growing more capable and more persistent, that endurance difference carries real operational weight. The DRDO-developed AIP module has cleared major technical trials and is also being retrofitted into INS Kalvari, extending the capability across the existing Kalvari class before the 75I boats are ever commissioned.

Yet the asymmetry is real and cannot be obscured. The most consequential dimension of China’s advantage lies not beneath the ocean but above it. International Institute for Strategic Studies reveals that China operates at least 245 defence and surveillance satellites, compared to India’s 26. China fields 92 intelligence, surveillance, and reconnaissance satellites and 81 designed for electronic intelligence and signals detection. India has 15 ISR satellites and a single satellite for electronic intelligence tasks.

Since 2006, China has launched more than 140 Yaogan-series surveillance satellites, which has given Beijing the ability to detect and track car-sized objects across the Indo-Pacific with near-real-time persistence. In March 2026, China launched eight more Yaogan satellites in a single Kuaizhou-11 rocket mission.

Retired Commodore Milind Kalshrestha, a veteran of the Indian Navy’s satellite communications and intelligence operations, has stated plainly that India is more than a decade behind China in both the number and capability of its surveillance satellites. That gap cannot be bridged quickly through procurement alone.

India’s strategic tradition has long favoured visible deterrence: warships, patrolling aircraft, the submarine on exercise. What the Chinese campaign in the Indian Ocean demands is something very different; information dominance. The ability to know where every vessel is, what it is carrying, and what it has been doing, continuously and across the full breadth of the IOR. The Deep Ocean Watch, the IFC-IOR, NavIC, and the fast-track procurement pipeline are the early chapters of that story. They are necessary. They are not yet sufficient.

The shift from reactive surveillance to active information dominance requires investment on a scale and at a pace that India’s defence establishment has not yet fully committed to. The satellite gap is the most stark illustration. Because China does not merely observe India’s maritime neighbourhood, it monitors it, persistently and in near-real time, from space. Until India closes that gap, its underwater sensor networks and fusion centres, however sophisticated, will operate with incomplete data against an adversary operating with comprehensive data.

Grey warfare is won not through a single decisive engagement but through the patient accumulation of information advantage. China understood that years ago. India is only now coming to understand it. The measures underway are a credible beginning. The next phase, space-based intelligence, autonomous systems deployed at scale, and data fusion across coalition partners, must follow without the delays that have characterised India’s defence programmes in the past. The Indian Ocean is not a problem that can be deferred.

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