China has significantly escalated its effort to block Philippine access to Bajo de Masinloc (Scarborough Shoal) over the past year, according to the security think tank SeaLight.

In a virtual forum organized by Stratbase ADR Institute on Tuesday, SeaLight director and former US Air Force officer Ray Powell said that from May 2024 to April 2025, China Coast Guard (CCG) and Chinese maritime militia (CMM) vessels broadcast more than 1.57 million automatic identification system (AIS) signals near the shoal — more than double the 724,000 broadcasts recorded between May 2023 and April 2024. The number of vessels involved also rose from 57 to 78.

“The area of intense activity expanded dramatically,” Powell said, noting that Chinese ships spread in all directions with a significant number moving east toward the Philippine mainland.

“The main takeaway is the doubling of Chinese activities and their push further east,” he emphasized. He explained that each AIS signal indicated an active tracking and reflected the overall intensity of China’s maritime presence.

In response, Philippine patrols around Bajo de Masinloc also increased. Between May 2024 and April 2025, Philippine Coast Guard (PCG) and Bureau of Fisheries and Aquatic Resources (BFAR) vessels transmitted 217,000 AIS signals from 11 ships, up from 55,000 signals from seven ships the previous year — a near fourfold jump.

Despite this surge, Philippine vessels have not been able to maintain a presence within the shoal itself.

Powell credited the PCG and BFAR for their “valiant efforts” to assert the Philippines’ rights but stressed that they were up against the “sheer volume” of Chinese ships.

“The Philippines continues to make its case in a visible way, but the Chinese presence is overwhelming,” he said.

National Security Council Assistant Director General Jonathan Malaya reaffirmed the country’s determination to uphold its sovereignty.

“There is risk to our servicemen there, but it is a risk worth taking because the shoal belongs to us,” Malaya said. He added that the government will continue regular maritime and aerial patrols to fly the Philippine flag and reinforce the nation’s claim.

Malaya warned of the practical consequences of China’s persistent presence, pointing out its severe impact on Filipino fishermen.

“Our fishermen, who have traditionally fished in these waters for generations, have had their access curtailed significantly,” he said. He also cited ongoing “dangerous maneuvers” by Chinese vessels that pose safety risks.

The Scarborough Shoal, located within the Philippines’ exclusive economic zone, has been a flashpoint in Manila-Beijing tensions for years.

In 2016, an international tribunal ruled in favor of the Philippines, rejecting China’s sweeping claims over the South China Sea. However, China has refused to recognize the ruling and has maintained a strong maritime presence in the contested waters.

Malaya said that despite being outnumbered, the Philippines has remained steadfast.

“We will not be deterred in asserting our rights and jurisdiction in Bajo de Masinloc,” he said, calling on allies and the international community to uphold the freedom of navigation and respect for international law in the region.