PHOTO SHOWS an underwater drone with Chinese markings from the Philippine National Police in Bicol, Dec. 30, 2024. — PHILIPPINE NATIONAL POLICE REGIONAL OFFICE 5

THE PHILIPPINE Coast Guard (PCG) on Tuesday said it had taken custody of a suspected sea drone recovered by Filipino fishers off northern Palawan, marking the latest in a series of similar recoveries since 2022.

The 12-foot-long drone found on Sept. 28 bore Chinese markings, was equipped with water temperature and depth sensors, and showed signs of corrosion from prolonged saltwater exposure, it said in a statement.

Authorities are analyzing the origin, operational history and potential national security risks of the sea drone, which the PCG said matches a series of similar devices recovered since 2022, at least three of which were traced to China through Chinese SIM cards and transceivers linked to a China-based contractor.

“This incident highlights the need for continued community awareness and a whole-of-nation approach to deter unauthorized activities in our waters,” PCG Commandant Admiral Ronnie Gil L. Gavan said in the statement.

The Chinese Embassy in Manila did not immediately reply to a Viber message seeking comment.

The Philippine Navy in April said at least three sea drones recovered within the country’s waters in the past two years had a “50% to 80%” likelihood of being deployed by China and might have been intended for mapping out the sea floor of Philippine waters, in preparation for underwater warfare.

Equipped with advanced technology, the suspected Chinese sea drones could measure water depth, temperature, salinity, detect underwater sounds and transmit the data via satellite communication.

“Previous forensic analyses of similar recovered autonomous underwater vessels have identified them as tools for advanced underwater surveillance and seafloor mapping,” the PCG said.

Chinese research vessels were detected in northern Philippine waters earlier this year, prompting concern among maritime authorities over the possible military applications of scientific data collected during unauthorized surveys.

The Philippines and China have long clashed over competing claims in the South China Sea, a strategic and resource-rich waterway through which trillions of dollars in annual maritime trade flows.

Beijing claims nearly all of the contested waters via a U-shaped, 1940s nine-dash line map that overlaps with the exclusive waters of the Philippines and neighbors like Vietnam and Malaysia.

A United Nations-backed tribunal in 2016 voided China’s sweeping claims for being illegal, a ruling that Beijing does not recognize. — Kenneth Christiane L. Basilio