Manila sends Teresa Magbanua within 100 yards of a Chinese survey ship off Itbayat

The Philippine Coast Guard sent its largest ship and an aircraft on Thursday to challenge a Chinese research vessel that had been sitting off Itbayat, in Batanes, since 28 September. Spokesman Jay Tarriela said the 97-metre BRP Teresa Magbanua closed to less than 100 yards of the Jia Hai Ke 7 at 7:55 a.m. and launched a rigid-hull inflatable boat that circled the survey ship while the crew issued radio challenges. A Chinese coast guard vessel moved in as well. Manila said the operation forced the research ship off its loitering position. Beijing's embassy had not answered a request for comment.

Tarriela, who speaks for the coast guard on South China Sea issues, said the Philippine move disrupted unauthorised marine scientific research and compelled the vessel to leave the spot where it had been holding. The coast guard said the operation was still under way, with Teresa Magbanua staying on the Jia Hai Ke 7 to see that it left the Philippine exclusive economic zone. The ship is the same Chinese-flagged survey vessel the coast guard has accused of spoofing its location while working off Batanes.

Why this patch of water is not a side show

Itbayat is the northernmost substantial island of the Philippines. It sits in the Luzon Strait, between Luzon and Taiwan, on the route used by submarines and by the cables that run between the two. Thirty-seven nautical miles northwest of Itbayat is inside the area Manila treats as its exclusive economic zone. A survey ship that stays for days, rather than transiting, is what the coast guard is treating as research without permission. Under the usual reading of the law of the sea, marine scientific research in another state's zone needs consent. China has not accepted that its ship required any.

The coast guard's choice of ship is part of the message. Teresa Magbanua, hull number 9701, is the largest vessel in the Philippine fleet, a multi-role response ship built for long presence rather than for a fight. Closing to 100 yards, about 91 metres, and putting a small boat in the water is a contact-range challenge. It is also the distance at which a misread helm order becomes a collision. The Chinese coast guard ship's arrival turns a research-vessel dispute into a two-ship standoff, which is the pattern Manila has seen farther south at Second Thomas Shoal and Scarborough, now repeated off Batanes.

The cable and the boundary talks

The South China Morning Post framed the same deployment against undersea-cable worries and against talks between Manila and Tokyo on maritime boundaries. Batanes has become a reference point in those talks because the line between Philippine and Japanese zones, and the gap toward Taiwan, runs through this strait. A Chinese survey ship holding station there for a week gives both the cable argument and the boundary argument a hull number. The coast guard has not said the Jia Hai Ke 7 was seen working on a cable. It has said the ship was conducting marine scientific research without authority, and that it had spoofed its position on earlier days.

No shot was fired. No boarding was attempted. The Philippine account is radio challenges, a close pass, a small boat circling, and a change in the survey ship's position. That is enough to log a confrontation and not enough to settle whether the ship has left the zone. Tarriela said monitoring continues. The next public fact will be whether Jia Hai Ke 7 is still inside the 200-nautical-mile line on Friday, and whether the Chinese coast guard ship stays with it.