The Philippine Coast Guard (PCG) said it detected a Chinese research vessel operating near the waters off Cagayan province, prompting immediate maritime and aerial actions to assert the country’s sovereign rights.
Using Canada’s Dark Vessel Detection program, the PCG monitored the Tan Suo Er Hao as it approached within 19 nautical miles of Cagayan. PCG Commandant Admiral Ronnie Gil Gavan ordered a maritime domain awareness (MDA) flight using a PCG Islander aircraft.
“The operation aimed to challenge the vessel’s presence, verify whether it was conducting marine scientific research without prior consent from the Philippine government—in potential violation of the Philippine Maritime Zones Act and the United Nations Convention on the Law of the Sea (UNCLOS)—and to assert the Philippines’ sovereign rights within its Exclusive Economic Zone (EEZ),” PCG spokesperson Commodore Jay Tarriela said.
The vessel, operated by the Chinese Academy of Sciences, serves as a mothership for deep-sea submersibles. PCG monitoring showed it departed Hainan province earlier this month and transited through the Philippine EEZ.
During the MDA flight, the PCG aircraft sighted the vessel eastward at coordinates 18°34.021′ N, 123°17.042′ E, about 55.78 nautical miles east of Santa Ana, Cagayan. Multiple radio challenges were issued, but the vessel did not respond.
Deputy Spokesperson of the Chinese Embassy Guo Wei rejected the PCG’s assertions, likening the situation to “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.” He stressed that UNCLOS guarantees international passage through the Luzon Strait.
The PCG reiterated its vigilance in safeguarding the country’s maritime domain and said it will continue to monitor and challenge unauthorized activities within the Philippine EEZ.