MANILA – A Chinese survey and research vessel, accompanied by six maritime militia ships, was spotted near Palawan island on Monday, according to an independent foreign monitor.

“China is now conducting a survey-in-force just 27nm from the Philippines’ coastline,” said Ray Powell, a former US Air Force officer and director of SeaLight, a maritime transparency project at the Gordian Knot Center for National Security Innovation at Stanford University, California.

The area lies within the Philippines’ exclusive economic zone. While the United Nations Convention on the Law of the Sea (UNCLOS) grants foreign vessels’ rights to navigation and overflight, more intrusive activities such as surveying or exploration require the consent of the coastal state.

Philippine officials have yet to release a statement on the latest sighting, but this is not the first time Chinese research and survey vessels have loitered in Philippine waters as Beijing’s assertiveness in the region grows.

“I should note that the ships have not yet entered into a typical 'lawnmower' survey pattern, so it may be they are simply there to send a message that China aims to assert its influence in these waters—much as they did last year to Vietnam,” Powell said.

The “lawnmower pattern” refers to a grid-like operation that indicates a bathymetric survey to map the seafloor.