Photo By: Phil. Coast Guard
MANILA, Philippines — The Philippine Coast Guard (PCG) conducted a Maritime Domain Awareness (MDA) flight on May 17, 2026 to challenge and drive away unauthorized Chinese marine scientific research (MSR) activities being carried out near Cay-2 and Cay-3 within the territorial waters of Pag-asa Island in the West Philippine Sea.
The operation was launched following the monitoring of the China-flagged research vessel Xiang Yang Hong 33 on May 16. The vessel, known for its advanced oceanographic survey capabilities, was reportedly conducting marine ecological surveys, bathymetric mapping, and deep-sea data collection within Philippine waters without authorization from the Philippine government.
According to the PCG, the Chinese research vessel was escorted by Chinese Coast Guard vessels CCG 5101 and CCG 5309, which deployed rigid-hulled inflatable boats (RHIBs) and rubber boats. Chinese personnel were observed landing and conducting activities on Cay-2 before proceeding toward Cay-3.
Photo By: Phil. Coast Guard
Authorities said the Xiang Yang Hong 33 departed Guangzhou, China on April 15 and entered the West Philippine Sea on April 18. Since then, the vessel has allegedly carried out systematic unauthorized marine scientific research activities across several maritime features within the Philippine exclusive economic zone (EEZ).
Upon the directive of PCG Commandant Admiral Ronnie Gil Gavan, PCG aircraft Islander 4177 conducted aerial surveillance operations over the Kalayaan Island Group (KIG). The MDA flight confirmed the continued presence of the Chinese research vessel and its support ships engaged in unauthorized activities near Sandy Cay 2.
The aerial patrol also documented the presence of twenty Chinese Maritime Militia Vessels (CMMVs) scattered around the waters of Sandy Cay 3 and 4.
The PCG stressed that the activities violate Philippine sovereignty and the provisions of the United Nations Convention on the Law of the Sea (UNCLOS), which requires prior consent from a coastal state before any marine scientific research can be conducted within its territorial sea.
“No consent was granted by the Philippine government to China or its vessels to conduct marine scientific research activities in these areas,” the PCG stated.
During the mission, the PCG aircraft issued multiple radio challenges ordering the Chinese vessels to stop their illegal activities and leave the area.
Admiral Gavan reaffirmed the PCG’s commitment to protecting the country’s maritime zones and sovereign rights in the West Philippine Sea.
“The PCG remains steadfast in defending our maritime zones. We will not allow any unauthorized foreign research or incursions into our territorial sea in Pag-asa Island in accordance with the directive of President Ferdinand Marcos Jr.,” Gavan said. “Our presence and patrols in the West Philippine Sea are consistent, lawful, and resolute.”
The PCG said it will continue to monitor the area and undertake necessary actions to safeguard Philippine jurisdiction and maritime interests. (Philippine Coast Guard)