China maps the seabed in preparation for a possible underwater war against the United States.

Title: Chinese research vessel conducts underwater mapping in strategic areas

For example, the “Dong Fang Hong 3,” a research vessel from the Chinese Ocean University, sailed between 2024 and 2025 in waters near Taiwan and Guam, where the United States has a naval base, as well as in strategic areas of the Indian Ocean, as shown by ship tracking data consulted by the press agency.

According to China, the vessel was conducting sediment surveys and climate research. However, a scientific article co-authored by researchers from the Chinese Ocean University shows that it also carried out detailed mapping of the deep seabed. Naval warfare experts and US Navy officials claim that the type of data collected by the “Dong Fang Hong 3” – through mapping and sensor deployment in the ocean – allows China to obtain a precise picture of the underwater conditions needed to deploy its submarines more effectively and track those of its adversaries.

42 active research vessels

However, the “Dong Fang Hong 3” does not operate alone. It is part of a larger operation of oceanic mapping and surveillance involving dozens of research vessels and hundreds of sensors. To track these operations, Reuters examined documents from the Chinese government and universities, including journal articles and scientific studies, and analyzed over five years of movements of 42 active research vessels in the Pacific, Indian, and Arctic Oceans using a ship tracking platform developed by the New Zealand company Starboard Maritime Intelligence.

While these research activities have civilian purposes – some exploration campaigns involve fishing areas or regions where China has mining exploration contracts – they also serve a military purpose, according to nine naval warfare experts who reviewed the press agency’s findings. Ship tracking data also shows that China’s seabed mapping efforts focus on areas of military significance around the Philippines, near Guam and Hawaii, and close to US military installations in the North Pacific.