China has recently expanded its use of ocean research ships.
Three years ago, they mostly surveyed the waters close to China.Activities of Chinese research ships in 2022
But last year, more ships ventured more frequently into the Western
Pacific Ocean, including areas of interest to China’s
military.Activities of Chinese research ships in 2024
From NYTimes by Chris Buckley / Graphics by Agnes Chang
Chinese research ships are studying the seas for science and
resources, but the data they gather could also be useful in a conflict
with Taiwan or the United States.
China has entered a new era of ocean exploration. Its top leader, Xi Jinping, has pushed to make China a maritime power — with a world-class navy, the largest deep-sea fishing fleet, and an interest in extracting minerals from the seabed.
He wants China’s research abilities to match those ambitions.
China’s scientific research ships are ranging farther and probing deeper, gathering information that could expand understanding of marine life and the impact of climate change.
But their findings could also serve China’s naval interests, including how it might deploy its submarines in the Pacific or try to track stealthier American ones.
Over time, the growing research fleet could give Beijing a powerful advantage in maritime competition with the United States.
“It is striking to see the rapidity with which China is catching up, at least in terms of scale,” said
Bruce Jones, a senior fellow at the Brookings Institution who is studying China’s ocean research effort.
China, he added, is “really making a play for the deep seabed as a kind of strategic space where they can lead.”
The Chinese research vessel Xiang Yang Hong 6.
China State-owned Assets Supervision and Administration Commission of the State Council
The ships have been studying waters that China’s navy considers strategically vital, including off Taiwan’s east coast and about 250 miles east and west of Guam, according to ship position data provided by Starboard Maritime Intelligence, a company with offices in New Zealand and Washington.
The ships made passes in parallel lines or in a tight grid, precise patterns that experts said suggested a methodical effort to collect information about the seabed that could, among other things, support military operations.
The New York Times identified these and other trends by looking at the Starboard data and reviewing dozens of technical reports and studies by scientists aboard the ships.
The Xiang Yang Hong 6, which is equipped with sonar and deep-sea sampling equipment, and five other Chinese research ships made 25 passes in parallel lines through the waters off Taiwan’s east coast last year, the Starboard data showed.
During the same period, Chinese vessels also traveled far from home to survey the waters around Guam, and resumed work east of the U.S. territory as recently as last month.
The Xiang Yang Hong 6 scanned the seabed east and west of Guam, a U.S. territory that hosts American military forces.
It surveyed an area larger than the United Kingdom.Activities of Xiang Yang Hong 6 in 2024
It also sailed in straight lines up and down the east coast of Taiwan, the self-ruled island that China wants to absorb.
Some of the research ships, such as the Tansuo No. 1, carry manned submersibles that
Chinese media reports say can travel as deep as six miles below the surface.
Many are equipped with advanced sonar to scan the ocean floor, along with buoys that transmit data about sea conditions.
China is also deploying
sea drones and
underwater gliders from some ships.
China, like other big seagoing countries, operates military ships that conduct ocean surveys.
But most of its research ships are civilian, run by government agencies, universities and institutes, which attract less scrutiny than navy ships, allowing China to operate more freely in sensitive waters.
Tansuo 1 is equipped for deep-sea exploration
Sources: Chinese Academy of Sciences, Scripps Institution of Oceanography
Surveying the Front Line of a Potential Conflict
Last February, a Chinese research ship named the Da Yang Hao sailed along Taiwan’s east coast, tracing a series of parallel lines over five days.
In the months that followed, five other Chinese research ships, including the Xiang Yang Hong 6, returned to the area, following similar routes.
They often moved at slow speeds, typically 8 to 10 miles an hour, ideal for mapping undersea features using sonar and other techniques, a science known as bathymetry.
Five ships collectively covered a broad area off of Taiwan’s east coast
Note: Data from Jan. 1, 2024 through Dec. 31, 2024.
Some ships edged close to Taiwan’s 12-nautical-mile territorial sea boundary, but did not appear to cross the line, meaning the Taiwanese government could do little to object.
But the potential military payoff from their research seemed clear.
“The big takeaway for me is: It appears that China is trying to collect bathymetric data on that part of the ocean without appearing like it is conducting a bathymetric survey,” said
Ryan D. Martinson, an assistant professor and expert on Chinese research ships at the U.S. Naval War College, who was speaking in a personal capacity.
Taiwan’s eastern coast is home to key air and naval bases, and if war broke out, the Chinese navy would try to seize control of the nearby seas.
That area of the Pacific is shaped by the Kuroshio Current, which brings relatively warm, salty waters from the Equator northward, along Taiwan’s east coast.
Off northeast Taiwan, the current meets a steep underwater shelf, creating conditions that complicate submarine navigation, several experts said.
Chinese military researchers wrote in
a study in 2010 that understanding the current would help China “better conceal ourselves and attack our enemies.”
J. Michael Dahm, a former U.S. Navy intelligence officer who is now a lecturer at George Washington University, described deep waters as “almost like a parfait dessert” in which temperature and salinity vary by layers, affecting how sound moves through the water.
“Having all of that data might help tell you that this is a good place for a submarine to hide or this is a bad place for a submarine,” Mr. Dahm said.
The information collected could also help China decide where to lay undersea mines and make steps toward a longer term goal of “detecting submarines at a distance,” said Tom Stefanick, a submarine
expert at the Brookings Institution.
Officials in Taiwan have reported
finding Chinese monitoring buoys off the island’s east coast, devices that may be part of an effort to gather useful information.
Surveying Near Guam, a U.S. Military Hub
Starting early last year, Chinese ships began surveying the seas near Guam, which hosts American bombers, submarines, marines and radar systems.
The Xiang Yang Hong 6 and other ships sailed back and forth, creating a dense grid of lines a mile apart.
“The tracks are so tightly packed, and all this was done in one year. Clearly, they were doing a bathymetric survey,” said
Sen Jan, a professor of oceanography at National Taiwan University, referring to the mapping of the seafloor.
One possible reason for the surveys off Guam is mineral exploration. A Chinese ocean mining association has registered
with the International Seabed Authority to search some areas east of Guam. But the waters west of Guam where Chinese ships surveyed “are not considered priority areas for mineral exploration. So these surveys may have been conducted for other purposes,” said
Christopher Kelley, a retired marine researcher at the University of Hawaii.
Several naval experts said surveys off Guam would also help the Chinese military better navigate the area with submarines. The Chinese research ships could also help locate American undersea cables and submarine detection technology, said
Bryan Clark, a former U.S. Navy submarine officer who is now a senior fellow at Hudson Institute.
“You can see how the Chinese might be trying to find locations where they can send out their submarines before conflict and have them hide out,” Mr. Clark said. From there, he added, they may be able to “pop up and attack U.S. forces or hold U.S. forces at risk.”
Growing Regional WorriesUnder international law, civilian research ships are allowed to operate in international waters, and even in other countries’ exclusive economic zones, provided they
seek permission.
But China’s growing use of these scientific ships has raised alarm throughout the Asia-Pacific region. (Beijing, for its part, has
bristled at U.S. Navy-operated ocean surveillance ships near the Chinese coast.)
“China’s expanding maritime reach deserves close scrutiny, especially its ‘research’ vessels that map seabeds, deploy sensors and pave the way for submarine operations,”
Jennifer Parker, a former Australian naval officer who is now an expert associate at the National Security College of Australian National University, wrote in an email. But, she added, “each voyage must be judged on evidence.”
In May,
the Philippines sent a coast guard ship and an aircraft to track a Chinese research ship that Manila said was illegally operating in the Philippines’s exclusive economic zone.
In March, a Chinese research ship sailing off southern Australia drew the government’s attention. Vietnam has also protested Chinese marine survey activities inside its exclusive economic zone.
“It’s hard for us to view this situation as normal,” Kuan Bi-ling, the minister of Taiwan’s Ocean Affairs Council, said in an interview, referring to China’s research ships and ocean monitoring equipment near Taiwan.
Despite the concerns, China’s research efforts continue.
Last month, the Xiang Yang Hong 1 and Xiang Yang Hong 5 arrived in seas east of Guam and resumed moving in grid-like patterns, methodically scanning what lies beneath.
Amy Chang Chien contributed reporting.
Map sources: Starboard Maritime Intelligence; Spire Global; Flanders Marine Institute; the University of Hawaii and the National Oceanic and Atmospheric Administration; Natural Earth.
Note: Graphics in this story use the automatic identification systems (AIS) position data of 49 active Chinese research vessels from Jan. 1 through Dec. 31 in both 2022 and 2024 to estimate ship paths. The ships were identified using ship registration and activity data, Chinese state media reports, government websites and academic publications. Ships do not always transmit information and may transmit incorrect information.
Chris Buckley, the chief China correspondent for The Times, reports on China and Taiwan from Taipei, focused on politics, social change and security and military issues.
