China’s Subsurface Presence in the Indian Ocean and India’s Options

In 2009, China deployed a flotilla of the People's Liberation Army Navy (PLAN) in the Indian Ocean as a part of the international effort to combat piracy in the Gulf of Aden.1 Since then, Chinese naval presence in the Indian Ocean has been steadily growing. China has cited protection of its maritime interests, including trade, as justification for maintaining a permanent presence in the Indian Ocean and establishing a logistics support base in Djibouti.2

In 2013, China announced the deployment of a Shang-class nuclear attack submarine in the Indian Ocean, ostensibly as part of its naval flotilla for anti-piracy patrols in the Gulf of Aden.3 Even though submarines, with their stealth characteristics, are unsuitable for missions requiring a visible naval presence, this marked the first reported presence of a Chinese submarine in the Indian Ocean Region (IOR). Following this deployment, Chinese submarines and support vessels have been making regular forays into the Indian Ocean, often alongside PLAN’s Anti-Piracy Escort Force (APEF) flotilla.4

In November 2023, the PLA Navy participated in the 'Sea Guardian 3' exercise with the Pakistan Navy. Chinese participation in the nine-day-long exercise included one Type-52D guided missile destroyer, two Type-54 frigates, a Type 039 conventional submarine, and a support vessel. According to reports, this marked the eighth visit of a Chinese submarine to the Indian Ocean since its initial reported deployment in 2013.5

Over the past decade, the deployment of Chinese research vessels and strategic satellite tracking ships in the IOR has increased.6 Research vessels conducting ocean surveys and gathering data, often for energy resources and marine environments research, are mostly owned and operated by state-affiliated organisations closely associated with the Chinese military.

The intersection between China’s oceanographic research and its extensive national security system reflects Beijing’s military–civil fusion strategy. This dual-use approach to oceanographic research raises questions about the true nature of these activities. Vessels involved in scientific research missions can also provide the People's Liberation Army (PLA) with crucial data about the world's oceans. The PLA can use insights from these missions to enhance its understanding of the dynamic undersea environment, a crucial step for deploying its subsurface assets.7

According to the US Department of Defense’s ‘China’s Military Power Report 2022’, China’s PLAN is ‘numerically’ the largest in the world.8 China operates around 60 submarines, including 12 nuclear submarines, with the total number expected to rise to 80 by 2035. Given China’s growing naval capabilities, it is likely that Chinese submarines would be deployed in the Indian Ocean even more frequently.

However, the landlocked geography of the Indian Ocean presents challenges for Chinese submarine deployment. Chinese submarines can enter the Indian Ocean through straits such as Malacca, Lombok, Sunda or Ombai-Wetar. Submarines must traverse the Malacca Straits on the surface due to safety concerns. The Sunda Straits are very shallow, with a mean depth of 50 meters. Sandbanks, oil platforms in the Sunda shelf, and numerous fishing vessels present significant navigation challenges for submarines. While the Lombok Strait and Ombai-Wetar are deep enough for submerged transit, sparse hydrographic details in these areas make navigation difficult.9

Given these navigational constraints, Chinese submarines are often accompanied by submarine-tender ships during their deployment in the Indian Ocean, which would be a significant giveaway during operational deployment. Chinese research vessels have been conducting ocean bed mapping along straits to facilitate submerged ingress into the Indian Ocean.

India’s Options

Undoubtedly, China’s growing subsurface presence in the Indian Ocean poses a strategic challenge to India. In response to China’s emerging subsurface presence, India has several options to safeguard its interests in the Indian Ocean.

Enhance Underwater Domain Awareness (UDA)

A key counter to China’s subsurface requires efforts towards comprehensive Underwater Domain Awareness (UDA), particularly around straits providing avenues for submerged ingress into the Indian Ocean. This involves deploying a network of seabed sensors, satellite surveillance, unmanned underwater vehicles and anti-submarine warfare (ASW) assets. Given the need to keep a vast geographical area under constant surveillance, a region-wide UDA effort may require collaboration with partner countries. Collaboration with countries such as the United States, Japan and Australia can enhance UDA capabilities through information sharing and joint exercises. Such collaborations can also help India gain access to advanced surveillance technology and best practices in maritime monitoring.

Enhance Maritime Domain Awareness (MDA)

Alongside UDA, India should continue with ongoing focussed efforts towards enhancing, and upgrading where necessary, existing Maritime Domain Awareness (MDA) capabilities and efforts. Collaborating with international partners to share MDA data and improve real-time situational awareness will be vital. Hence, collaboration efforts with international partners under the aegis of the Information Fusion Centre–Indian Ocean Region (IFC-IOR) should continue with an aim to enhance comprehensive MDA coverage.

Strengthen Naval Capabilities

Expanding the Indian Navy's fleet and modernising its existing assets will be crucial to maintaining a robust naval presence in the Indian Ocean. Investment in indigenous shipbuilding capabilities and the acceleration of current defence procurement processes are essential. A focussed approach towards developing and deploying long-endurance autonomous underwater vehicles (AUVs) and remotely operated vehicles (ROVs) to enhance its underwater surveillance capabilities is essential. These unmanned systems can provide persistent surveillance and gather critical data on underwater activities.

Strengthen Strategic Partnerships

India should strengthen its strategic partnerships with key regional and global powers. Initiatives such as the Quadrilateral Security Dialogue (Quad) with the United States, Japan and Australia can play a pivotal role in ensuring a free and open Indo-Pacific. Joint naval exercises, intelligence sharing and coordinated patrols can help counterbalance China's influence in the region. Additionally, India can deepen its defence cooperation with countries in the IOR such as Indonesia, Singapore and Sri Lanka. Bilateral agreements for base access, joint training and logistical support can enhance India's operational reach and capabilities.

Develop Forward Operating Bases

Establishing and maintaining forward operating bases in strategically important locations such as the Andaman and Nicobar Islands can enhance India's ability to monitor and respond to Chinese naval activities including subsurface presence. These bases can serve as logistical hubs and provide quick deployment options for the Indian Navy. Forward operating bases can enable rapid response to any maritime contingencies. Upgrading infrastructure at these bases, including runways, docking facilities and communication systems, will be crucial.

Leverage Technology and Innovation

Investing in cutting-edge technologies and innovation will be critical for maintaining a strategic edge in maritime operations. India should focus on developing and integrating advanced technologies such as artificial intelligence (AI), machine learning, and big data analytics for maritime surveillance and decision-making.

In coping with the challenges of adversarial subsurface presence, the combination of enhanced naval capabilities, strategic partnerships and comprehensive UDA will be key to maintaining regional stability and safeguarding India's strategic interests. Through a multifaceted approach that includes military, diplomatic and technological measures, India can secure its position as a dominant maritime power in the Indian Ocean Region.

Views expressed are of the author and do not necessarily reflect the views of the Manohar Parrikar IDSA or of the Government of India.

• 1.  Andrew S. Erickson and Justin D. Mikolay, “Welcome China to the Fight Against Pirates”, U.S. Naval Institute Proceedings, 1 March 2009.
• 2.  Joshua T. White, “China’s Indian Ocean Ambitions: Investment, Influence and Military Advantage”, Brookings Institution, June 2020.
• 3.  P.K. Ghosh, “Chinese Nuclear Subs in the Indian Ocean”, The Diplomat, 12 April 2015.
• 4.  Prakash Panneerselvam, “China’s Emerging Subsurface Presence in the Indian Ocean”, The Diplomat, 3 December 2022.
• 5.  Vishnu Som, “Exclusive: Chinese Submarine, Warships In Karachi - What It Means For India”, NDTV, 13 November 2023.
• 6.  Cate Cadell, “Chinese PLA-Linked Vessels Map the Indian Ocean for Submarine Warfare”, The Washington Post, 10 January 2024.
• 7. Matthew P. Funaiole, Brian Hart and Aidan Powers-Riggs, “Surveying the Seas: China’s Dual-Use Research Operations in the Indian Ocean”, CSIS, 10 January 2024.
• 8.  “2022 China Military Power Report”, US Department of Defense, 2022.
• 9. Prakash Panneerselvam, “China’s Emerging Subsurface Presence in the Indian Ocean”, no. 4.