Photo credit: PCG

The Philippine Coast Guard (PCG) announced it will deploy aircraft and patrol vessels to challenge and drive away four Chinese research vessels allegedly conducting unauthorized marine scientific research within Philippine waters.

Using Canada’s Dark Vessel Detection (DVD) System, the PCG said it tracked the movements of the Chinese vessels and determined that they were carrying out research activities without the approval of the Philippine government, which authorities said violates international maritime laws, including the United Nations Convention on the Law of the Sea (UNCLOS).

Among the vessels monitored was the XIANGYANGHONG 33, an advanced oceanographic survey ship spotted near Quirino Atoll off Palawan. Authorities said the vessel is capable of deep-sea exploration, seafloor mapping, and geophysical surveys.

Another vessel, SHI YAN 1, was detected west of Itbayat, Batanes. The research ship is reportedly equipped with advanced hydro-acoustic and marine science technology used for precise ocean data collection.

The JIA GENG, a deep-sea research vessel capable of deploying unmanned underwater vehicles, was also monitored northeast of Itbayat, while the ZHUHAIYUN — described as the world’s first intelligent drone mothership — was spotted northwest of Pangasinan. The vessel can reportedly deploy more than 50 unmanned aerial, surface, and underwater vehicles for large-scale ocean surveys.

The PCG said it is now closely monitoring the ships’ movements and preparing immediate maritime and aerial operations to challenge the vessels and push them away from Philippine waters.

“In furtherance of the policy directive of President Ferdinand R Marcos Jr, the Philippine Coast Guard remains steadfast in safeguarding the country’s maritime domain. We will not tolerate any illegal marine scientific research conducted without our government’s consent. We are deploying aircraft and vessels to challenge and drive away these unauthorized vessels to protect Philippine sovereignty and sovereign rights,” said PCG Commandant, Admiral Ronnie Gil Gavan.

The latest incident adds to growing maritime tensions between the Philippines and China in the West Philippine Sea, where both countries have repeatedly clashed over territorial claims and the presence of Chinese vessels inside the Philippines’ exclusive economic zone (EEZ).

Under UNCLOS, foreign states must first secure permission from a coastal state before conducting marine scientific research within its EEZ or continental shelf. Philippine officials have repeatedly accused Chinese vessels of carrying out unauthorized activities in disputed waters.

In recent months, the Marcos administration has intensified maritime patrols and strengthened defense cooperation with allies including the United States, Japan, and Australia amid increasing Chinese activity in the region.