The Philippine Coast Guard (PCG) is now monitoring the presence of three Chinese research vessels within the country’s territorial waters, particularly off the waters of Zambales and Palawan.

PCG spokesperson Commodore Jay Tarriela said the two research vessels were last monitored together off the waters of Palawan.

“These vessels are suspected of engaging in illegal marine scientific research (MSR), prompting the PCG Commandant, Admiral Ronnie Gil Gavan, to issue immediate orders to intercept and challenge them,” said Tarriela.

He said the first vessel, Bei Diao 996, was last spotted 185 nautical miles off the coast of Zambales and is involved in MSR activities about 40 nautical miles west of Bajo de Masinloc.

The Bei Diao 996 is a civilian research vessel with dual-use capabilities, specializing in testing underwater acoustic sensors and sonar equipment.

It is China's largest test ship for deep-sea operations and the world's largest SWATH catamaran, designed for stable performance in adverse weather.

The other two vessels, Xiang Yang Hong 10 and Zhuhai Yun, were monitored 195 nautical miles off the coast of Rizal, Palawan and are suspected to be conducting joint MSR operations near Balagtas Reef.

The Xiang Yang Hong 10 is a multi-purpose research vessel capable of deep-sea surveys and supporting unmanned autonomous underwater vehicles (AUVs) for seafloor mapping and environmental monitoring.

It features icebreaking capabilities and a dynamic positioning system for precise operations.

The Zhuhai Yun, on the other hand, is the world's first intelligent unmanned drone carrier and is designed for oceanographic research but has significant military dual-use potential, including mapping submarine routes and deploying smart mines.

In deploying PCG vessels, Tarriela said they always make it a point to challenge Chinese vessels entering the country’s territorial waters as part of the conduct of maritime law enforcement in the West Philippine Sea.

“We always see to it that we challenge them. We are highlighting the fact that it is not part of the maritime jurisdiction of the People's Republic of China and that they do not have authority to conduct such maritime law enforcement patrol,” said Tarriela.

Aside from the three Chinese research vessels, Tarriela said three China Coast Guard vessels returned to the vicinity of the Bajo de Masinloc after the three weather disturbances that hit the country.

“Our commandant has deployed our Coast Guard vessel to once again carry out our maritime law enforcement patrol in the area,” said Tarriela.