Photo credit: PCG

The Philippine Coast Guard (PCG) has documented the presence of the Chinese oceanographic research vessel Tong Ji in the waters near Bajo de Masinloc, marking the first time the vessel has been monitored in the area.

According to the PCG, Tong Ji, also known as Tongji, is China's first intelligent ocean-class oceanographic research vessel. The ship was built by state-owned CSSC Huangpu Wenchong Shipbuilding for Shanghai-based Tongji University and was designed to support marine geology, chemistry, biology, and other scientific studies.

The vessel, which entered service in 2025, measures more than 81 meters in length and has a range of about 8,000 nautical miles. It is equipped with advanced autonomous navigation capabilities, modular laboratories, and systems that allow it to deploy unmanned equipment for research and engineering operations.

Its appearance at Bajo de Masinloc comes amid continued monitoring by Philippine authorities of Chinese vessels operating inside the country's exclusive economic zone in the West Philippine Sea. Previous sightings of Chinese research ships in the area have prompted concerns over possible marine scientific research activities and their potential dual-use capabilities. Some vessels are capable of conducting seabed mapping, underwater surveys, and supporting offshore engineering work.

Bajo de Masinloc, also known internationally as Scarborough Shoal, lies about 124 nautical miles off Zambales and falls within the Philippines' 200-nautical-mile exclusive economic zone. Despite a 2016 arbitral ruling invalidating Beijing's expansive claims in the South China Sea, China continues to maintain a presence in the disputed waters.

The latest sighting of the Tong Ji adds to the growing list of Chinese research vessels monitored by the PCG in the West Philippine Sea, underscoring Manila's continued efforts to track foreign maritime activities in waters it considers part of its sovereign rights and jurisdiction.