As the Philippine Coast Guard plane descended toward the country's most strategically important outpost in the disputed South China Sea, passengers' phones lit up with a roaming alert: "Welcome to CHINA."
Among those on board were Senator Risa Hontiveros and Coast Guard spokesperson Jay Tarriela, both outspoken critics of Beijing's actions in the South China Sea.
After landing on Saturday, they spoke to island residents to reaffirm that Thitu Island, "is ours", even as Chinese Coast Guard vessels, a People's Liberation Army Navy ship, and some Chinese fishing boats lingered within sight of the shore. China's persistent presence has pushed islanders, who rely on those waters for their livelihood, farther from the sea they once freely navigated.
At just 37 hectares (0.37 square kilometres), the coral-fringed Thitu, known to Filipinos as Pag-asa, or "Hope", is the largest and most prized of the nine Philippines-held features in the Spratly archipelago, located 450 kilometres (280 miles) from the mainland.
Its 400-odd residents live modestly, far from the trappings of city life; yet their quiet presence reinforces the Philippines' claim of sovereignty at a time of mounting Chinese pressure.
The visit by Hontiveros and Tarriela, coming as rhetoric on both sides has sharpened, is likely to draw scrutiny from Beijing and add strain to an already tense territorial dispute.
"We will never give up the Kalayaan Island Group, including Pag-asa," Hontiveros told residents, referring to the portion of the Spratly Islands that Manila claims and administers, including Thitu.
Both officials have been repeatedly singled out in Chinese Embassy statements and online messaging campaigns, part of a broader effort to shape narratives about the South China Sea. Manila's appointment of a dedicated foreign ministry spokesperson on maritime affairs reflects a growing sensitivity within government ranks as China's physical and informational pressure intensifies.
On Pag-asa, China's pressure is not abstract. Among those listening to Hontiveros was 45-year-old fisherman Rando Asiado, who said the long-standing presence of Chinese vessels has kept him from venturing to rich fishing grounds near Subi Reef and the nearby Sandy Cays.
"There are times when Chinese Coast Guard vessels would chase us away, so we are forced to stay on one side of the island. And when we try to fish on the other side, Chinese drones fly over us," said Asiado, who has been living on the island since 2012.
China claims most of the South China Sea, despite the Permanent Court of Arbitration in The Hague invalidating the claims in a 2016 ruling.
Just 14 nautical miles from Thitu, Subi Reef is one of seven artificial islands China has built in the Spratlys to support its sovereignty claims. Some artificial islands are equipped with surface-to-air missiles, aircraft hangars and runways.
Approaches by the Chinese Coast Guard have become so routine that Filipino fishermen now cast their nets in less productive waters to avoid confrontation. China's actions in the South China Sea, which have included water-cannoning and close-quarter manoeuvring of ships, have resulted in collisions and injury to Philippine crews.
China has maintained its actions are lawful and professional, accusing Manila's vessels of intruding into its territory.
"We're not afraid because we know we're in the right, but they're using ships while we only have small boats. We don't stand a chance, so to avoid trouble, we just steer away," said 51-year-old fisherman Ronnie Cojamco.
(Reporting by Karen Lema; Editing by Michael Perry)
