Coast Guard scrambles aircraft and vessels as Chinese research ships stray into Philippine waters

The Philippine Coast Guard sent an aircraft and several vessels after detecting Chinese research ships illegally entering the country’s sovereign waters, testing the Philippines’ maritime response.

Advanced oceanographic survey vessel Xiangyanghong 33’s history trail tracked through AIS. Photo from Jay Tarriela’s Facebook page.

Manuel Mogato | May 5, 2026

MANILA — The Philippine Coast Guard (PCG) sent an aircraft and several vessels after detecting Chinese research ships illegally entering the country’s sovereign waters, testing the Philippines’ maritime response.

In a statement, Vice Admiral Ronnie Galvan, the head of the Coast Guard, said four Chinese research vessels were violating the United Nations Convention on the Law of the Sea (UNCLOS) by operating without legal authority or prior consent from the Philippine government. (Also read: Navy rejects maritime cooperation with China)

“We will not tolerate any illegal marine scientific research conducted without our government’s consent,” Galvan said.

“We are deploying aircraft and vessels to challenge and drive away these unauthorized vessels to protect Philippine sovereignty and sovereign rights.”

Galvan said China’s Xiangyanghong 33, an advanced oceanographic survey vessel of the Xiang Yang Hong class, equipped for deep-sea research, seafloor mapping, geophysical exploration, and support of submersibles, was detected operating within the Philippines’ exclusive economic zone.

He said the Chinese vessel was observed northwest of Rizal town in Palawan, and within the vicinity of Quirino Atoll. (Also read: Chinese vessels observe Philippine maritime drills with allies)

Another Chinese research vessel, Shi Yan 1, a SWATH-hulled research vessel specialized in marine science and hydro-acoustics, featuring dynamic positioning, noise reduction, and advanced sensors for precise geophysical and acoustic data collection, was monitored steaming west of Itbayat, Batanes.

A third research vessel, Jia Geng, a modern deep-sea research vessel equipped with acoustic sensors, weather radars, and capable of deploying unmanned underwater vehicles for multidisciplinary oceanographic studies, was observed northeast of Itbayat, Batanes.

The fourth Chinese research vessel, Zhuhaiyun, the world’s first intelligent drone mother ship, designed to deploy and control over 50 unmanned aerial, surface, and underwater vehicles simultaneously for comprehensive three-dimensional ocean surveys, with autonomous navigation capabilities, was in the vicinity northwest of Bajo de Masinloc.

Galvan said the Coast Guard continued to monitor the four vessels’ movements in accordance with Philippine laws, international maritime law, and UNCLOS. (Also read: Chinese warship fires flares as Philippine Coast Guard plane patrols in disputed sea)

The Coast Guard had issued a radio call, challenged, and demanded that the Chinese vessels leave the Philippines’ maritime waters.