China is conducting extensive undersea mapping and monitoring operations across the Pacific, Indian, and Arctic Oceans, according to a Reuters analysis. The Ocean University of China’s research vessel Dong Fang Hong 3 has repeatedly operated near Taiwan, Guam, and strategic areas of the Indian Ocean between 2024 and 2025. The vessel, officially described as conducting soil and climate research, has also been involved in deep-sea mapping and testing underwater sensors capable of detecting submerged objects.

Naval experts and U.S. officials cited in the report say the collected seabed data could significantly enhance China’s submarine warfare capabilities by improving navigation, detection, and deployment strategies. The mapping activity is concentrated near U.S. military bases in the Philippines, Guam, and Hawaii. Analysts describe the initiative as part of China’s “civil-military fusion,” combining civilian research with military applications.

The project, referred to by Chinese researchers as the “Transparent Ocean,” aims to provide real-time information on underwater conditions. Experts warn that this growing network of vessels and sensors could give China a strategic advantage in submarine operations and pose new challenges for the U.S. Navy.