Chinese deep-sea test ship ignores Taiwan coast guard calls in restricted waters off Pingtung

A Chinese deep-sea equipment test ship, Bei Diao 996, sailed into Taiwan's restricted waters south of Qixingyan, a rocky outcrop off the Hengchun Peninsula at the southern end of Pingtung County, on Sunday morning, the Taiwanese newspaper Liberty Times reported. The ship approached the area at about 7 a.m. local time with no clear purpose, and Taiwan's Coast Guard Administration sent patrol boat PP-3518 to monitor it after receiving a report, according to the newspaper.

Coast guard crew hailed the Chinese vessel by name over the radio and told it to leave in line with Taiwanese law, but the ship did not answer at any point, the Liberty Times said. The report listed the ship's maritime identity number, call sign and IMO number, and said its track had been logged by Taiwan Adiz, a social-media page that follows military movements around the island. The newspaper did not say how long the ship stayed inside the restricted zone or whether it had left by the time of publication.

In commentary cited by the newspaper, the page said it trusted the coast guard to keep watching the surrounding seas around the clock and to enforce the law, and argued that the incursion showed Beijing had never given up harassing Taiwan at sea and in the air. That is a judgment by the page, not a finding by Taiwanese authorities.

Bei Diao 996 is already known to coast guards in the region. In July 2025 the Philippine Coast Guard said the ship had entered the Philippine exclusive economic zone without authorisation and was suspected of carrying out marine scientific research about 40 nautical miles west of Scarborough Shoal, after leaving Guangdong province on 16 June that year. Philippine officials described it as China's largest deep-sea research test ship and the world's biggest small-waterplane-area twin-hull catamaran, a design meant to stay stable in rough seas.

Philippine Coast Guard spokesman Jay Tarriela said at the time that the vessel had dual-use capabilities and specialised in testing underwater acoustic sensors and sonar equipment. The Philippine service said it had followed the ship with a satellite dark vessel detection programme supplied by Canada, which is designed to track ships that switch off their transponders.

Weeks later, the Philippine Daily Inquirer reported that the roughly 100-metre ship had been operating off Batanes province since 3 September 2025. Ray Powell, director of the SeaLight maritime monitoring project, said its track showed a lawnmower or grid pattern, which the newspaper noted is the kind of path ships follow when carrying out bathymetric surveys to map the seafloor. Two other Chinese survey ships, Dong Fang Hong 3 and Zhi Hai, were in the same area at the time, the report said.

Taiwan's coast guard has pushed Chinese research ships away before. In September 2025 it said it had driven two of them, Xiang Yang Hong 18 and Dong Fang Hong 3, out of waters north of Taiwan, broadcasting a warning and using manoeuvres to force the first ship to change course near Pengjia Islet, the Taipei Times reported. The agency accused the ships at the time of ignoring international maritime rules and urged China to stop actions that undermine regional peace and stability.

Sunday's report places a ship that Philippine officials have tied to sonar testing and seabed survey work in restricted waters off Taiwan's southern coast. The Liberty Times described the vessel's intent as unclear and reported no response from the ship to the coast guard's calls.