Philippines Escorts Chinese Research Vessel out of EEZ, Unlike Australia and NZ

Epoch Times

09-05-2025

The Philippines has shown a different attitude to the presence of a CCP research vessel in its territorial waters than Australia and New Zealand in March this year with its coastguard escorting the ship out of its Exclusive Economic Zone (EEZ).
The Tan Suo 3 was first detected illegally conducting marine scientific research about 92 nautical miles (nm) (171 kilometres) off Burgos, Ilocos Norte, on May 1. It is believed to have been undertaking deep-sea mapping to support the People's Liberation Army-Navy (PLA-N) submarine operations.
The Philippine Coast Guard (PCG) deployed its lead patrol vessel, the BRP Teresa Magbanua, and an aircraft to force the CCP ship outside the country's 220-nautical-mile EEZ. It left without incident and took up a position 250 nm out.
While in Philippines waters, the Tan Suo 3 deployed a manned submersible vehicle, the Shenhai Yongshi or Deep-Sea Warrior, which is designed for deep-sea exploration and scientific research, and is capable of diving to a depth of 4,500 metres.
The PCG recovered an unidentified piece of yellow-coloured equipment, which it says could be part of the instruments used by the Chinese in their research operations.
The Tan Suo 3 leaves the Philippines' waters. Courtesy Philippines Coastguard.
The Philippines' rapid and no-nonsense reaction to the incursion of a CCP research ship into its EEZ is in sharp contrast to those of New Zealand and Australia.
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In January this year, New Zealand's National Institute of Water & Atmospheric Research (NIWA) invited the Tan Suo Yi Hao to conduct 'deep-sea exploration of marine biodiversity in New Zealand's subantarctic waters' over 56 days.
It was the CCP's second collaboration with New Zealand, using its deep-sea manned submersible Fen Dou Zhe.
This expedition marked the first exploration of the Puysegur Trench, an 800 kilometre (km) long, deep cleft in the seafloor, with the Fen Dou Zhe diving 6 km to the bottom 32 times.
A NIWA spokesperson said the involvement of the Tan Suo Ti Hao was necessary because
the Fen Dou Zhe is the only research-focused submersible in the world currently able to dive to the deepest parts of the oceans (about 11,000 metres).
'This expedition brought back never-before-seen footage of life in the Puysegur Trench, as well as the first ever biological specimens, and images of the sea floor,' the spokesperson told The Epoch Times.
At a function at the Chinese Embassy in Wellington, the CCP's Ambassador Wang Xiaolong called the research 'a crown jewel of bilateral evolving mutually-beneficial partnership.'
The Tan Suo Yi Hao. Photograph from the CCP Institute of Acoustics.
Asked by this newspaper whether there were any defence and security concerns with having a CCP ship mapping areas in which a submarine could potentially be concealed, New Zealand's Defence Minister Judith Collins said the NZ Defence Force was aware of its location and movements, 'as the Defence Force maintains maritime domain awareness of foreign ships to our region.
'However, the NZDF wasn't actively monitoring it as it had approval to visit New Zealand and conduct operations here with NIWA.'
She would not be drawn on whether New Zealand had informed Australia of the vessel's presence before, during, or after it left New Zealand's territorial waters and sailed along Australia's southern coastline.
It was a trajectory that seemed to take Australia by surprise, with Prime Minister Anthony Albanese telling reporters he would 'prefer' the ship hadn't done so, but that it hadn't broken any international laws.
The Australian Department of Defence deployed a P-8A maritime patrol aircraft (MPA) to monitor the ship's activities.
In a statement, Chief of Joint Operations Vice Admiral Justin Jones said the Tan Suo Yi Hao entered Australia's EEZ from the Tasman Sea on March 27 and subsequently passed through the Bass Strait between 28 and 29 March, making steady progress. It then spent some time approximately 400 nautical miles (741 km) southeast of Perth.
Returning to China via the southern coast of Australia was not the most direct route for the vessel, and nor did the CCP give any reason why it halted its progress several times, once for 12 hours and then a further 17 hours, while it was east of the Australian coast.
That led a number of China-watchers to speculate that it had deployed
the Fen Dou Zhe to explore and map the Diamantina Trench, between 550 and 630 nm from Australia's coast.
Ray Powell, a 35-year veteran of the US Air Force who's currently director of SeaLight and Project Lead at Stanford University's Gordian Knot Center is one of those.
He noted
A map of the path taken by the Tan Suo Yi Hao in 2023, when it repeatedly traversed the area of the Diamantina Trench after sailing past the southern coast of Australia. Courtesy Ray Powell/via Starboard_NZ
Powell noted the ship is owned by China's Institute of Acoustics, which has 'deep PLA ties going back decades, as is clearly outlined
The Chinese Academy of Sciences has signed
What Does Sea Mapping Achieve?
Submarines rely on the ocean floor relief to navigate and hide; therefore, understanding the seabed's shape and composition is essential.
With a new submarine base due to be constructed at Perth to act as the southern hemisphere centre of operations for the AUKUS fleet, there are obvious strategic advantages to the CCP if being able to covertly surveil—and perhaps even respond to—submarine movements from a deep trench which wouldn't be detected by the U.S. and Australia.
The 'most obvious' reason for the CCP to carry out deep-sea research off Australia and New Zealand would be to facilitate its submarine force deployments, including those that are armed with nuclear missiles, at 'strategic deep-sea locations,' Powell concluded.
The activities of the research vessel occurred only weeks after
While in the southern Tasman, they carried out a
The Australian Department of Defence was asked by The Epoch Times for comment on any security risk posed by the work of the Tan Suo Yi Hao off Australia's coast, whether New Zealand informed them of the presence of the ship in the South Pacific Ocean, and whether existing counter-submarine technology could detect a foreign submarine in the Diamantina Trench.
However, they declined to comment.