PMMA, Zambales—The Armed Forces of the Philippines on Thursday said that the Chinese flag research vessel “Shen Kou” initially sighted loitering in the country’s exclusive turned off its Automatic Identification System (AIS) to avoid being monitored by the country's forces.

“As of the latest report, the vessel already turned off its AIS so we are only relying to our visual monitoring of its movement and our maritime patrol will determine the status of its locations and activities,” AFP spokesperson Col. Francel Margareth Padilla told reporters in an ambush interview.

She said the vessel’s “unauthorized presence” was last tracked at the eastern seaboards of the country and it was reportedly “checking the conditions” of the Philippine waters.

“We also got a photo that they are hoisting down a certain equipment so possibly with that equipment they are trying to see the ocean bed—what’s on the sea floor because after it was taken a photo, they immediately hoisted it up,” Padilla said.

“We cannot speculate why they did it but of course, they are turning it off means not being detected,” Padilla said.

Padilla said the AFP is still conducting maritime patrol, utilizing its naval and air forces, to visually monitor the survey vessels.

“We have been sending maritime patrols regularly to monitor the activity of this vessel and so, as of today, we have an ongoing maritime patrol mission,” she stressed.

Citing the military’s initial report, Philippine Navy spokesperson for the West Philippine Sea, Commodore Roy Vincent Trinidad, said the Chinese vessel was also conducting marine research and some studies in the country’s waters.

Trinidad said the Chinese survey ship’s action in the area cannot be considered as illegal as even the United Nations Convention on the Law of the Sea “is hardly implementing policies” when it comes to research and studies of the maritime domain.

SHEN KOU was last spotted in a zigzag movement in the vicinity of Viga, Catanduanes.

Padilla said the AFP conducted radio challenges against it but did not respond.

“We did not sight any personnel on the main deck and there are also no responses to all of the communications that we are trying to conduct with them,” she said, adding that “it says two things; either they don’t want to engage or its actually a vessel in distress.”

Aside from detecting the presence of the foreign vessel, Padilla said the maritime patrol will also determine how fast the survey ship moves and its further destination.