PCG deploys assets against Chinese vessel in disputed waters over alleged unauthorized research

MANILA, 11 OCTOBER 2026 —

The Philippine Coast Guard (PCG) has deployed aircraft and vessels to intercept a Chinese deep-sea research ship, the Tan Suo Yi Hao, accused of conducting "unauthorized" marine scientific research within the Philippines’ exclusive economic zone (EEZ) near Hubo Reef in the West Philippine Sea, marking the latest escalation in maritime tensions.

The move underscores Manila’s firm stance against what it calls Beijing’s expanding presence in disputed waters, where Chinese vessels—including fishing boats, research ships, and military assets—have increasingly operated without consent. The PCG’s actions follow surveillance confirming the Tan Suo Yi Hao conducted diving operations inside the Philippines’ EEZ, a violation of international law under the UN Convention on the Law of the Sea (UNCLOS), which requires prior notification and consent for such activities.

PCG Commandant Admiral Ronnie Gil Gavan ordered vessels to confront the Chinese ship, which departed from Hainan’s Sanya waters on October 2 and entered the Philippine EEZ on October 9, according to tracking data from Dark Vessel Detection and the Automatic Identification System. On October 10, the ship was stationary 12 nautical miles northwest of Katimugan Bank, and the next day, it was spotted five nautical miles west-northwest of Hubo Reef, moving eastward.

Despite multiple radio challenges from the PCG, the Tan Suo Yi Hao did not respond.

Gavan accused China of using research and fishing vessels to "thinly spread operational capabilities" and pressure the Philippines into accepting Beijing’s expansive claims in the South China Sea. "Any seabed survey, sampling, or mapping undertaken by Tan Suo Yi Hao without such consent is illegal and unauthorized," the PCG stated, adding that China had not sought Philippine approval for the research.

The PCG also monitored two China Coast Guard vessels—5306 and another—near Hubo Reef, along with two Chinese navy ships in nearby waters, including one 22.8 nautical miles northeast of Escoda Shoal.

The incident comes amid broader regional concerns over China’s assertive maritime activities, which Manila has vowed to counter. Gavan reiterated the PCG’s commitment to uphold Philippine sovereignty, stating, "We will execute the guidance of the President not to lose even a square inch of our territory and jurisdiction." The 2016 arbitral award, which invalidated China’s historic claims in the South China Sea, remains a key legal basis for the Philippines’ stance.

For Malaysia and regional observers, the confrontation highlights the risks of escalating tensions in the South China Sea, where overlapping claims and military posturing could disrupt maritime trade and security. The Philippines’ firm response may also signal a hardening of regional resolve against unilateral actions in disputed waters, with potential implications for ASEAN’s collective stance on sovereignty and resource rights.

The next steps will depend on China’s reaction and whether further diplomatic or military engagements follow.

Related: Admiral Ronnie Gil Gavan