Japan Institute for International Affairs (JIIA) - China’s Marine Survey Ships as a Security Challenge for Japan and the Region
Research Group on 'China and Maritime Interests / Order' 2026-# 1
China is accelerating its expansion into the open seas. In June 2025, Japan’s attention was drawn to the first simultaneous deployment of two Chinese aircraft carriers in the northwestern Pacific near the Japanese islands of Okino-torishima and Minami-torishima, where they conducted operational exercises. China’s naval strategy had incorporated the new concept of “oceanic presence and polar expansion” as early as 2018 to complement traditional “near-sea defense and far-sea defense”.2 Before conducting naval operations, however, China must first collect various types of oceanographic data and gain an in-depth understanding of seabed topography, ocean currents, tidal patterns and other conditions. For this reason, China’s marine survey activities must have intensified even before the People’s Liberation Army (PLA) Navy began its operations in earnest.
For many years, the activities of Chinese marine survey ships did not receive as much attention as those of the PLA Navy and the China Coast Guard, or even the Chinese fishing boats serving as maritime militia that are now well-known for their role in gray-zone operations. However, increased use of open-source Automatic Identification System (ASI) data has made the global activities of Chinese marine survey ships better known. In particular, the 2025 circumnavigation of the Australian continent by the Chinese oceanographic research vessel Tan Suo Yi Hao(IMO: 8315451) sparked controversy in Australia. Since then, some observers have viewed Chinese oceanographic research activities as preparations for submarine warfare against the United States3.
Conversely, the domestic factors driving the expansion of China’s marine surveys remain unclear. Aiming to help address this research gap by examining Chinese policy documents and analyzing AIS data from a ship that sailed the waters around Japan in collaboration with ingeniSPACE, this paper argues that the Xi Jinping administration’s marine policy under the Military-Civil Fusion (MCF) strategy has turned China’s marine survey ships into instruments of gray-zone operations aimed at intimidating neighboring countries.
For the full article by Professor Aki Sakabe-Mori at the Japan Institute for International Affairs, click here.