Indian Navy To Deploy Underwater Sensor Network To Monitor Chinese Submarines In Indian Ocean

The Indian Navy, in collaboration with the Defence Research and Development Organisation (DRDO), plans to deploy advanced underwater sensors to detect submarine movements—an ambitious move aimed at bolstering maritime security in the Indian Ocean Region (IOR), which is critical for India’s geopolitical and economic interests amid the growing presence of foreign submarines, particularly from China.

The new strategic plan focuses on creating a network of underwater sensors capable of detecting submarine activity in the Ninety East Ridge, the Andaman and Nicobar Islands, and the Bay of Bengal. These sensors include advanced hydroacoustic systems, similar to those used by the United States and Japan in their "Fish Hook Undersea Defense Line" in the Pacific, which stretches from Japan to Southeast Asia. The Indian Navy plans to deploy similar systems at the northern and southern tips of the Andaman and Nicobar Islands to provide early warning of Chinese submarine activity in the region.

“India faces significant challenges from the People’s Liberation Army Navy (PLAN) expanding its submarine operations in the region. The four-week survey of the Ninety East Ridge by China’s ‘silent’ research vessel Dong Fang Hong 3 last month has heightened concerns about mapping underwater environments for submarine operations,” said a senior defence official, adding that Chinese vessels frequently enter the IOR under the guise of scientific research, which is often linked to intelligence-gathering missions.

The Ninety East Ridge, a linear intraplate rise ideal for submarine navigation, has been a focal point of concern for India due to its strategic importance in monitoring and preventing undetected incursions by foreign submarines.

“The troubled waters of the IOR are further complicated by Pakistan’s acquisition of eight Yuan-class submarines with air-independent propulsion (AIP) systems from China,” added the official.

While the Indian Navy's current submarine fleet—comprising 13 conventional diesel-electric submarines, including nine Sindhughosh-class and four Shishumar-class vessels—lacks the numerical and technological edge to effectively counter underwater threats from Pakistan and China, the development of underwater sensors marks a critical step toward enhancing India’s anti-submarine warfare (ASW) capabilities and maintaining its strategic pre-eminence in the IOR.

The vast expanse of the IOR includes key chokepoints like the Malacca Strait and the Sunda Strait, making underwater domain awareness (UDA) vital for regional security.

The indigenous underwater sensors under development include passive and active sonar systems, magnetic anomaly detectors (MAD), and superconducting quantum interference devices (SQUIDs).

While passive sonar systems, which detect noise emitted by submarines without emitting signals, will be crucial for stealth surveillance, the deployment of active sonar systems will enable precise detection and ranging in high-threat scenarios.