Marine vessel trackers show China’ research/ survey vessel is still in Sri Lanka. The Chinese survey vessel Da Yang Yi Hao entered Indian waters shortly after Operation Sindoor, advancing strategic interests for both China and Pakistan. On May 7, India launched strikes on nine terror sites in Pakistan and Pakistan-occupied Kashmir (PoK) in response to the April 22 Pahalgam terror attack.

The Da Yang Hao is a Chinese research vessel designed for deep-sea exploration and marine resource surveys. It is part of China’s expanding fleet of advanced oceanographic vessels, which are often described as having dual-use capabilities, serving both scientific and potential military purposes.

The Da Yang Hao is described as a “floating laboratory” equipped with over 50 pieces of surveying and monitoring equipment and 400 square meters of laboratories dedicated to “marine geology, ecology, and atmospheric” studies– as per China.The vessel can conduct seismological studies of the seabed, map ocean floors, and collect oceanographic data such as currents, bathymetry, and salinity, which are relevant for both scientific research and potential military applications, including submarine warfare. It is equipped with advanced sensors and possibly autonomous underwater vehicles (UUVs), enabling it to gather detailed data on underwater terrain and conditions.

The Da Yang Hao embarked on its maiden voyage to the Atlantic in December 2019, conducting seismological studies of the seabed. As of recent reports, it has been spotted in various regions, including the Fijian Exclusive Economic Zone (EEZ) and the Indian Ocean Region (IOR). In 2021, it was flagged for unauthorized activities in Palau’s EEZ, raising concerns about its data collection, particularly in areas critical for submarine operations like the Kyushu-Palau Ridge.

The presence of the Da Yang Hao and other Chinese research vessels in the Indian Ocean Region (IOR) has raised significant concerns in India due to their potential dual-use capabilities and strategic implications. While China insists that vessels like the Da Yang Hao are for scientific research, India and other regional powers suspect they are used for intelligence-gathering and military purposes. The vessel’s ability to map ocean floors, track submarine movements, and collect oceanographic data (e.g., bathymetry, salinity, and currents) is seen as critical for submarine navigation and anti-submarine warfare (ASW) planning, which could benefit the Chinese People’s Liberation Army (PLA) Navy.

Da Yang Hao has been spotted in the IOR, including near the Bay of Bengal and the Sunda Strait, often coinciding with India’s military activities, such as ballistic missile tests (e.g., the Agni-5 test in March 2024). This timing fuels suspicions that the vessel is monitoring Indian naval operations or missile launches.

In May 2025, following India’s Operation Sindoor (a response to a terror attack in Pahalgam), the Da Yang Hao’s presence in Indian waters was seen as a strategic move to test India’s maritime surveillance capabilities and support Pakistan, China’s ally, by gathering intelligence on Indian naval movements, including those of INS Vikrant. Indian government sources suggest the vessel could map submarine routes and intercept communications to aid China’s plans for a military logistics base in Pakistan (e.g., Jiwani or Gwadar) as part of the China-Pakistan Economic Corridor (CPEC).

The Da Yang Hao’s operations align with China’s broader “String of Pearls” strategy, which involves establishing maritime footholds across the IOR (e.g., Hambantota in Sri Lanka, Gwadar in Pakistan, and Djibouti) to secure trade routes and enhance strategic influence. India perceives this as a challenge to its dominance in the IOR, its traditional sphere of influence.

The vessel’s activities, along with those of other Chinese ships like the Xiang Yang Hong 03, which docked in the Maldives in 2024, have strained India’s relations with smaller IOR states like the Maldives and Sri Lanka. These countries, under pro-China governments, have granted docking privileges to Chinese vessels, raising concerns in New Delhi about data sharing and strategic encirclement. The Da Yang Hao is believed to be equipped to intercept acoustic signatures of Indian submarines and monitor missile test firings at India’s Integrated Test Range (ITR) on APJ Abdul Kalam Island. This data could be relayed to Chinese spy satellites, enhancing Beijing’s surveillance capabilities in the region.

The Indian Navy actively tracks Chinese vessels like the Da Yang Hao in the IOR, using satellite imagery and other intelligence to monitor their movements. In 2024, the Navy was reported to be closely watching the Da Yang Hao and other vessels like the Xiang Yang Hong 01 and Yuan Wang 03.

India has raised objections to the docking of Chinese research vessels in neighboring countries like the Maldives and Sri Lanka, viewing their presence as a diplomatic snub and a security threat. For instance, Sri Lanka initially resisted allowing the Shiyan 06 to dock in Colombo in 2023 due to Indian concerns but later relented.

The Da Yang Hao’s operations in the Indian Ocean Region, particularly near India’s coast or during sensitive military activities, have sparked concerns in New Delhi about potential espionage and strategic encirclement. India views the vessel as part of China’s broader effort to expand its naval and geopolitical influence in the IOR, often in collaboration with regional allies like Pakistan. The Indian Navy continues to monitor the Da Yang Hao closely.