Survey vessels have become important actors in China’s efforts to assert its maritime claims in the South China Sea. Since 2019, China has deployed survey ships four times in direct response to Southeast Asian oil and gas activity as part of widely reported standoffs. But China also conducts a significant number of surveys in the South China Sea that don’t make headlines. Automatic identification system (AIS) data on Chinese surveys from 2020 and 2021 demonstrates that China’s survey activities span the entire South China Sea and regularly occur in the exclusive economic zones (EEZs) of its Southeast Asian neighbors. Such surveys for marine scientific research or oil and gas exploration without permission are illegal under international law; those for purely military research are legal but run counter to China’s stated opposition to foreign military surveys within the EEZ.
What Lies Beneath: Chinese Surveys in the South China Sea | Asia Maritime Transparency Initiative
Survey vessels have become important actors in China’s efforts to assert its maritime claims in the South China Sea. Since 2019, China has deployed survey ships four times in direct response to Southeast Asian oil and gas activity as part of widely reported standoffs. But China also conducts a...
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The number and extent of surveys conducted underscores the rapid growth and development of China’s survey fleet, the largest and most active in the Indo-Pacific. It is impossible to determine what type of research these vessels were conducting based on AIS alone. These surveys did not follow the grid or “lawnmower” pattern typical of bathymetric and seismic surveys, as seen in three of the four surveys discussed above in retaliation for Southeast Asian oil and gas activity.
The purpose of a survey, whether commercial, scientific, or military, is important for determining its legality. The survey activities of ships flagged to other nations can usually be distinguished by the vessel’s operator. In the United States, for example, military surveys are done by the U.S. Navy, marine scientific research is conducted by universities or civilian organizations like the National Oceanic and Atmospheric Administration, and commercial surveys are conducted by private companies. But the lack of such distinctions among China’s state-owned fleet makes it impossible to confidently identify the purpose of most surveys. China’s pursuit of civil-military integration makes it likely that data obtained by Chinese survey vessels is shared among scientific, military, and commercial entities.