Manila: The Philippine Coast Guard (PCG) has deployed a vessel and an aircraft to intercept and escort a Chinese research ship allegedly conducting unauthorized marine scientific research within the country’s exclusive economic zone (EEZ).
The vessel, identified as the Chinese Research Vessel Tan Suo 3, was first detected on May 1, 2025, approximately 92 nautical miles off the northern coast of Ilocos. According to a PCG statement released Monday, the ship’s movements raised suspicions due to irregular patterns that suggested it was engaging in marine research rather than simply exercising freedom of navigation.
“These activities infringe upon the Philippines' sovereign rights,” the PCG stated, adding that it responded by launching a maritime law enforcement operation to confront the vessel and stop the unauthorized activity.
During the operation, Philippine authorities observed the deployment and retrieval of a manned submersible named Shenhai Yongshi (Deep-Sea Warrior), which is capable of reaching depths of 4,500 meters. The PCG said such equipment is typically used for deep-sea scientific missions.
Additionally, a Rigid Hull Inflatable Boat was seen recovering a yellow-colored object believed to be marine research equipment.
“These findings confirm that China is conducting marine scientific research within the Philippine EEZ without proper authorization,” the PCG concluded.
