The Philippine Coast Guard (PCG) and the Chinese Embassy exchanged sharp allegations on Friday after a Chinese research vessel was detected operating near the northern waters of the West Philippine Sea (WPS).

The PCG said it detected the Chinese Research Vessel (CRV) Tan Suo Er Hao approaching within approximately 19 nautical miles off the coast of Cagayan province using Canada’s Dark Vessel Detection program.

The detection of a Chinese ship followed by the deployment of a PCG Islander aircraft to conduct a Maritime Domain Awareness (MDA) flight to question the vessel’s presence, determine whether it was conducting marine scientific research without Philippine consent, and to assert the country’s sovereign rights within its Exclusive Economic Zone (EEZ).

PCG spokesperson for the WPS, Commodore Jay Tarriela, said the operation was conducted in accordance with the Philippine Maritime Zones Act and the United Nations Convention on the Law of the Sea (UNCLOS), which require prior authorization for marine scientific research within a coastal state’s EEZ.

Public highway comparison

In response, Chinese Embassy deputy spokesperson Guo Wei defended the movement of a Chinese research vessel through the Luzon Strait, comparing it to travel on a “public highway permitted under international law.” 

“This is like driving on a public highway that international law clearly allows everyone to use—only to be accused of trespassing because someone insists a side road is the only ‘approved’ route,” Guo said. 

He said the strait, including the Bashi, Balintang, and Babuyan channels, remains open to international navigation under UNCLOS.