The submersible drones — believed to be made and owned by China —found in the waters around the Philippines are critical in underwater warfare, a Philippine Navy official disclosed on Wednesday.

According to Philippine Navy spokesperson for the West Philippine Sea, Rear Admiral Roy Vincent Trinidad, the submersible drones found in various parts of the country have different capabilities that can be utilized for different uses, such as commercial, academic, scientific research, and military.

“The yellow drone is designed to collect what we call bathymetric data—like water depth, salinity, conductivity, and oxygen content,” Trinidad said during the resumption of the Senate Special Committee on Philippine Maritime and Admiralty Zones into the submersible drones found in Philippine waters.

“The black drone has the same capabilities, but it also comes equipped with an AVS, or Acoustic Vector Sensor. It picks up sound and helps analyze how sound propagates or travels underwater,” he added.

There have been at least six submersible drones found in the Philippines so far, three of which were presented during the hearing, including the black drone that proved to have relayed a signal to China.

The black drone is the most recently discovered submersible drone currently in the possession of Philippine defense officials. It was found in Sabtang, Batanes, in February.

“We haven't conducted level 2 exploitation yet, only level 1 exploitation,” Trinidad said.

‘China connections’

According to Trinidad, based on their forensic investigation, the black drone also contained a SIM card from a Chinese telecommunications company. However, he clarified that this does not automatically mean it is of Chinese origin or linked to any specific entity.

“We're not saying that. What we're saying is that, based on the forensic examination, it transmitted a signal to China,” he said when asked whether China was involved in the deployment of the said drones.

For his part, Senator Francis Tolentino, chair of the Senate panel, said the discovered submersible drones in different parts of the country, alleged espionage by Chinese nationals in Makati City, and text scams are all connected to the People’s Republic of China.

“They’re all part of the same thing: espionage. So let’s not treat this as just about the drone. It started with the device found by the PNP—the gadget, the MC (mobile communication) grabber—that was capable of intercepting your texts and messages in malls. We talked about that,” he said.

“We also discussed the scams. Then there was what the NBI (National Bureau of Investigation) presented—gadgets seized in El Grande, Palawan. All of these are consistent. They’re all related. And all the leads so far point toward the People’s Republic of China,” he added.

The development came as tensions between the Philippines and China increased due to their overlapping claims in the West Philippine Sea.

China claims the vast South China Sea, including the West Philippine Sea. Recently, confrontations between the Philippine Coast Guard and China Coast Guard and militia vessels have significantly increased.

In 2016, the Philippines won a landmark arbitration case against China before the Permanent Court of Arbitration. The ruling invalidated China's expansive claims in the South China Sea.

China has rejected the award, calling it “illegal, null and void.”