Vol.31. October 15. 2025
What is happening in East Asian Maritime Security? The Research Institute for Peace and Security (RIPS) publishes the biweekly newsletter, the information on maritime security relevant to East Asia and Japan's territory. |
Statistical Data and Analysis (as of October 15)
In the first half of this month, China repeatedly engaged in unilateral actions in violation of international law.
The Chinese oceanographic research vessel conducted what appeared to be oceanographic research within Japan’s Exclusive Economic Zone (EEZ) in the East China Sea. As unapproved oceanographic research activities in the area are not permitted, the Japan Coast Guard (JCG) repeatedly demanded that the activities be halted. Nevertheless, similar activities by the vessel were repeatedly confirmed on September 28, 30, and on October 1, 2, 4, 5, 6, 13 and 14.
As part of Japan’s efforts, the Japan-Philippines Vice-Ministerial Strategic Dialogue was held on October 2, during which the two sides exchanged views on security and maritime cooperation, which are essential to promoting the Free and Open Indo-Pacific (FOIP). On October 7, the Japanese and Philippine defense ministers held a VTC, during which they reaffirmed close cooperation on maritime security and regional stability. It was also reported that the JCG and Taiwan’s Coast Guard Administration are strengthening their cooperation through regular joint maritime exercises.
[Statistical Data as of October 15]
Japan Coast Guard (JCG) daily updates the statistical data on the number of China Coast Guard vessels entering in the contiguous zone around the Senkaku Islands and intruding into Japanese territorial waters. The below is from the website of JCG.
https://www.kaiho.mlit.go.jp/
mission/senkaku/senkaku.html
Sep. |
Contiguous zone |
Territorial
Waters |
Oct. |
Contiguous zone |
Territorial
Waters |
30 |
4 |
|
7 |
4 |
|
Oct. |
Contiguous zone |
Territorial
Waters |
8 |
4 |
|
9 |
4 |
|
1 |
8 |
|
10 |
4 |
|
2 |
4 |
|
11 |
4 |
|
3 |
4 |
|
12 |
4 |
|
4 |
4 |
|
13 |
4 |
|
5 |
4 |
|
14 |
4 |
|
6 |
4 |
|
|
|
|
|
|
|
|
Date |
Topics |
9/30 |
On September 30, the Chinese oceanographic research vessel Xiang Yang Hong 22 was observed within Japan’s Exclusive Economic Zone (EEZ), approximately 386 kilometers west of Amami Oshima Island in Kagoshima Prefecture, extending what appeared to be a pipe-like object into the sea from its stern. The JCG reportedly issued a radio request via its patrol vessel, asking that the research activities be halted, stating that such activities are not permitted without Japan’s consent. Subsequently, the oceanographic research vessel reportedly exited the area. According to the JCG, the same oceanographic research vessel was also confirmed to have conducted what appeared to be research activities on September 28 within Japan’s EEZ, near the current research area. |
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9/30 |
The Philippine Coast Guard (PCG) has taken custody of an alleged underwater drone recovered by local fishermen in the waters near Brgy. Barangonan, Linapacan, Palawan. This incident highlights ongoing illegal marine scientific research in Philippine waters, amid a pattern of similar events involving foreign-origin autonomous underwater vehicles (AUVs).
On September 28, 2025, fishermen from Sitio Tapic, Brgy. New Colaylayan, Linapacan, discovered the approximately 12-foot-long device during routine fishing operations. Later that evening, they turned the AUV over to Coast Guard personnel. The alleged drone had been safely transported and secured at PCG Station Linapacan.
Preliminary observations show that the device features a Conductivity-Temperature-Depth (CTD) sensor—a compact probe designed to measure seawater salinity, temperature, and depth, which are key parameters for oceanographic profiling. The sensor includes Chinese labeling (“海水盐度传感器”) and a serial number (CTD-20090334), along with visible corrosion from prolonged saltwater exposure. It is mounted on a rugged metal frame, typical of components in autonomous underwater vehicles commonly known as “underwater drones.”
This recovery fits into a series of similar incidents in Philippine waters dating back to July 2022, including devices found in Pasuquin, Ilocos Norte (July 2022); off the Zambales coast (September 2022); Calayan Island, Cagayan (August 2024); Initao, Misamis Oriental (October 2024); and San Pascual, Masbate (December 2024). At least three of those prior recoveries have been linked to Chinese deployment, based on evidence such as China Telecom SIM cards, iridium transceivers connected to Beijing-based HWA Create (a defense contractor), and battery packs marked by China Electronics Technology Group Corporation.
Previous forensic analyses of similar recovered AUVs have identified them as tools for advanced underwater surveillance and seafloor mapping. The integrated CTD sensor allows for the collection of data on salinity, temperature gradients, depth, and acoustic propagation—essential for bathymetric charting and environmental monitoring. Recovered units have shown capabilities for autonomous data processing, storage, and satellite transmission, with one case revealing encrypted communications to mainland China during operations. |
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10/2 |
On October 1, the JCG says a patrol ship saw the Chinese oceanographic research vessel extending a pipe-like object in waters roughly 400 kilometers west of Amami Oshima Island. The same vessel was seen conducting what appeared to be survey operations in adjacent waters within Japan's EEZ on September 28 and 30.
On October 2, Chief Cabinet Secretary Hayashi Yoshimasa said the JCG has continuously demanded that China stop the activity. He said the government has also lodged a strong protest with China through diplomatic channels, saying any marine scientific survey in Japan's EEZ is not acceptable without its consent and is extremely regrettable, and that it must stop immediately. He said Japan will continue to deal with the situation resolutely and calmly. NHK World |
|
10/2 |
On October 2, the Japan-
Philippines Vice-Ministerial Strategic Dialogue was held in the Philippines.
During the dialogue, both sides exchanged views on economic security and cooperation in security and maritime areas which is essential for promoting a Free and Open Indo-Pacific (FOIP) in the midst of an increasingly severe and complex global strategic environment.
The two sides also held candid and detailed discussions on the situation in the East China Sea and South China Sea, Japan-U.S.-Philippines cooperation, and various regional and international issues including ASEAN, and they concurred to continue working closely to move forward. |
Ministry of Foreign Affairs of Japan |
|
10/2 |
On October 2, the JCG confirmed the Chinese oceanographic research vessel Xiang Yang Hong 22 extending a pipe-like object into the sea within Japan's EEZ, approximately 385 kilometers west of Amami Oshima Island. This research vessel is conducting activities within the EEZ off Amami Oshima Island for the fourth time, following operations on September 28, 30 and October 1. The JCG's patrol ship issued a radio warning demanding that the research be halted. Subsequently, the research vessel exited Japan’s EEZ. |
Jiji Press News (Japanese) |
|
10/3 |
On October 3, the Japan Maritime Self Defense Force (JMSDF) confirmed one Russian Udaloy Ⅲ class destroyer (hull number 543), one Steregushchiy Ⅲ class frigate (hull number 337) and one Boris Chilikin class replenishment oilers sailing southwest in the waters 80km northeast of Tsushima Island (Nagasaki Prefecture). These vessels sailed southwest through the Tsushima Strait and navigated to the East China Sea. |
|
10/3 |
It has been revealed that the JCG and Taiwan’s Coast Guard Administration are working to regularize joint maritime exercises. They are also considering future exercises involving allied and like-minded partners.
In June, Japan and Taiwan dispatched large patrol vessels to conduct a joint exercise in international waters south of the Sakishima Islands in Okinawa Prefecture, simulating maritime rescue operations. This marked the second such exercise since diplomatic ties between the two sides were severed. In contrast to the joint exercise held in July last year off the Boso Peninsula in Chiba Prefecture, the vessels came within visual range of each other and strengthened on-site coordination through information sharing and adjustments to the search area.
The Japanese government officially frames the joint exercise with Taiwan as part of an "exchange" based on memorandums of understanding on maritime rescue concluded between the two sides' liaison agencies in 2017 and 2024.
Alongside these memorandums, the JCG and Taiwan’s Coast Guard Administration have, in recent years, quietly exchanged visits between Tokyo and Taipei by senior officials, including the head of Taiwan’s agency. Through discussions, consultations, and site visits, they have deepened their cooperation. China’s increasingly coercive behavior in the waters around the Senkaku Islands in Okinawa Prefecture and near Taiwan lies behind this enhanced coordination. In early September, ruling party lawmakers from Japan and Taiwan held discussions on enhancing cooperation between their coast guard agencies and promoting personnel exchanges.
In addition to its partnership with Taiwan, the JCG is expanding its maritime security cooperation through both bilateral and so-called “minilateral” frameworks involving a small number of countries such as Japan–U.S., Japan–Philippines, Japan–India, Japan–U.S.–South Korea, Japan–U.S.–Philippines, and the Quad (Japan–U.S.–Australia–India). These efforts aim to maintain and strengthen a maritime order based on the rule of law. Yomiuri Shimbun News (Japanese) |
|
10/3 |
The Philippines is closely watching Beijing's plans for a nature reserve at the disputed Scarborough Shoal in the South China Sea, its chief of armed forces said on October 3, adding it was important that the shoal does not become militarised. Manila has called last month's announcement by China of plans for a reserve at the shoal a "clear pretext for occupation".
Philippines' Armed Forces Chief General Romeo Brawner said his country "will not allow" what happened at Mischief Reef to happen to Scarborough Shoal. The Philippines claims Mischief Reef, which is within its Exclusive Economic Zone in the South China Sea, but it was occupied in the 1990s by China, which has since built a military base on it. "Once they build a structure there, that would be a different story. We have several options that we could do. Diplomatically, we could file protests, but we are watching so that we will not have a repeat of Mischief Reef," Brawner told a forum organised by foreign correspondents.
Both China and the Philippines claim the Scarborough Shoal, but sovereignty remains unresolved. China took control in 2012 after a standoff and has since stationed its coast guard and fishing vessels there. China said a national nature reserve at Scarborough Shoal was important to preserve the atoll's ecosystem. Reuters |
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10/4 |
On October 4, the JCG confirmed that the Chinese oceanographic research vessel Xiang Yang Hong 22 was deploying a pipe-like object into the sea within Japan's EEZ, approximately 420 kilometers west of Amami Oshima Island. A JCG patrol vessel issued a radio warning demanding a halt, and the research vessel moved to the Chinese side about an hour later. Since September 28, the same research vessel has been observed operating multiple times in the surrounding EEZ. Kyodo News (Japanese) |
|
10/5 |
On October 5, the JCG confirmed that the Chinese oceanographic research vessel Xiang Yang Hong 22 was deploying what appeared to be a pipe-like object into the sea from the side of the vessel, within Japan’s EEZ, approximately 383 kilometers west of Amami Oshima Island. The same research vessel was also observed conducting what appeared to be research activities in Japan’s EEZ near the same waters on September 28 and 30, as well as on October 1, 2, and 4. |
|
10/6 |
On October 6, the JCG confirmed that the Chinese oceanographic research vessel Xiang Yang Hong 22, which had been suspected of conducting oceanographic research since October 5 in Japan's EEZ off Amami Oshima Island, had moved to the Chinese side of the Japan-China median line in the East China Sea. The same vessel has been repeatedly observed conducting similar activities in the surrounding EEZ since September 28. |
|
10/6 |
On October 3, the JMSDF confirmed one Russian Vishnya class Intelligence ship (hull number 535) sailing southwest in the waters 90km northeast of Tsushima Island (Nagasaki Prefecture). From October 3 to 4, this vessel sailed southwest through the Tsushima Strait. Subsequently, on October 6, this vessel sailed south through the waters between Okinawajima Island and Miyakojima Island (both in Okinawa Prefecture) and navigated to the Pacific Ocean. |
|
10/6 |
On October 4, the JMSDF confirmed one Chinese Dongdiao class Intelligence ship (hull number 796) sailing northeast in the waters 60km southwest of Cape Tappizaki (Aomori Prefecture). This vessel sailed east through the Tsugaru Strait and navigated to the Pacific Ocean. |
|
10/6 |
On October 5, the JMSDF confirmed one Russian Udaloy Ⅲ class destroyer (hull number 543), one Steregushchiy Ⅲ class frigate (hull number 337) and one Boris Chilikin class replenishment oilers sailing southwest in the waters 60km northwest of Iriomotejima Island (Okinawa Prefecture). From October 5 to 6, these vessels sailed southwest through the waters including the contiguous zone between Yonagunijima Island (Okinawa Prefecture) and Iriomotejima Island and navigated to the Pacific Ocean. |
|
10/7 |
Japan-Philippines Defense Ministerial VTC (excerpt)
On October 7, a Video Teleconference was held between Japan's Minister of Defense and the Philippines' Secretary of National Defense.
The two Ministers welcomed that the application of the Japan-Philippines Reciprocal Access Agreement (RAA), which came into effect on September 11, to the Bilateral HA/DR Exercise, and the delivery of support goods for those affected by the earthquake off the coast of Cebu Province, demonstrates the deepening relationship between Japan and the Philippines. Additionally, they confirmed their commitment to continue working closely together, based on the spirit of OCEAN, to contribute to maritime security as well as regional stability and peace. Ministry of Defense of Japan |
|
10/10 |
Statistics on Scrambles Conducted Through the First Half of FY2025
The Japan Joint Staff released its statistics on scrambles conducted through the first half of FY2025 (April 1 to September 30, 2025). The total number of scrambles during this period was 265. During the same period in FY2024 (April 1 to September 30, 2024), the total number of scrambles was 358. Including estimates, approximately 75% of the scrambles were in response to Chinese aircraft, approximately 22% to Russian aircraft, and approximately 3% to others.
During the same period, on May 3, an airspace violation occurred involving a helicopter launched from a China Coast Guard vessel that had intruded into Japan’s territorial waters near the Senkaku Islands.
In addition, active operations by Chinese and Russian aircraft were observed, including: – more frequent passages of Chinese unmanned aerial vehicles (UAVs) between Yonagunijima Island and Taiwan compared to
the first half of FY2024; and – flights by Russian Tu-95 bombers and fighter jets over the Sea of Japan. |
|
10/10 |
Monthly Statistics on Scrambles(September)
Japan Joint Staff released its monthly statistics on scrambles. In September, Japan Air Self Defense Force (JASDF) conducted 44 scrambles. The most scrambles are against Chinese aircrafts (34 times). The others were against Russian aircrafts (8 times) and so on. |
|
10/10 |
On October 10, the JMSDF confirmed two Chinese Luyang III class destroyer (hull number 123 and 124) and one Chinese Fuchi class replenishment ship (hull number 902) sailing northwest in the waters 200km southeast of Miyakojima Island (Okinawa Prefecture). These vessels sailed north through the waters between Okinawajima Island and Miyakojima Island and navigated to the East China Sea. |
|
10/12 |
Activities of another research vessel have been confirmed within Japan's EEZ off Amami Oshima Island in Kagoshima Prefecture, where the Chinese oceanographic research vessel Xiang Yang Hong 22 had been operating since late September, government sources revealed on October 12. According to data analysis by the Sankei Shimbun, although the Xiang Yang Hong 22 left the area on October 6, it resumed operations within Japan’s EEZ on October 12. The area includes gas fields that China is developing. From September 26 to October 12, the vessel reportedly crossed the median line at least 25 times.
According to government sources, the vessel confirmed to be operating within Japan’s EEZ off Amami Oshima Island on October 12 was the Xiang Yang Hong 03. On October 1, the Xiang Yang Hong 18 was also confirmed to have been navigating near the Senkaku Islands. China is stepping up its maritime activities in the East China Sea to assert its influence.
Analysis based on data from the vessel tracking website VesselFinder indicates that the Xiang Yang Hong 22 departed from Hengsha Island near Shanghai, China, on September 25 and headed toward the East China Sea. From September 26 onward, the vessel was observed repeatedly crossing the median line at a slow speed of around 2 knots—roughly the pace of a walking person. The analysis confirmed that between September 26 and October 12, the vessel crossed the median line on 11 separate days, for a total of 25 times. Plotting these routes on a map reveals “peculiar” patterns of movement. There were also eight round trips, each spanning approximately 60 kilometers.
The sea area also contains the Shirakaba gas field (called Chunxiao in Chinese), which China is actively developing. Currently, 18 drilling rigs are installed for gas extraction, and moves to install three more rigs have been confirmed this year.
Regarding the movements of the Xiang Yang Hong 22, Professor Chisako Masuo of the Graduate School of Social and Cultural Studies, Kyushu University, an expert on China's maritime policy, analyzed that, “It is clear this is not purely for academic research purposes. The rigs are multifunctional and can be equipped with security functions such as surveillance equipment. By expanding and linking these capabilities, the aim may be to strengthen intelligence gathering in surrounding waters and establish operational bases.” |
Sankei Shimbun News (Japanese) |
|
10/13 |
On October 12, Chinese coast guard ships used powerful water cannons and rammed and slightly damaged an anchored Philippine government vessel off an island inhabited by Filipinos in the disputed South China Sea, the Philippine coast guard said.
There were no injuries among Filipino crewmen of the BRP Datu Pagbuaya, part of the fisheries fleet that provides support to Filipino fishermen. The Chinese coast guard targeted Pagbuaya off the Philippines-occupied Thitu island in the latest flare-up of the long-simmering territorial disputes involving Manila, Beijing and four other governments.
Two other Philippine fisheries vessels were targeted with water cannons in the October 12 faceoff, which occurred at least 1.6 nautical miles (nearly 3 kilometers) from Thitu island. There were no damages or injuries, Philippine coast guard spokesperson Commodore Jay Tarriela said in a news briefing on October 13.
The Chinese coast guard accused the Philippine vessels of illegally entering what it called Chinese waters near a cluster of sandbars known as Sandy Cay, which lies between Thitu and China’s artificial island base called Subi and “ignoring repeated stern warnings from the Chinese side.” It said it “took control measures against the Philippine vessels in accordance with the law and resolutely drove them away.” |
|
10/13 |
Meeting between Senior Deputy Minister Namazu and Under Secretary Hooker (excerpt)
On October 13 in Tokyo, a meeting was held between Japan’s Senior Deputy Minister for Foreign Affairs and U.S. Under Secretary of State for Political Affairs.
The two sides led the U.S.-Japan Dialogue on a Free and Open Indo-Pacific to discuss priorities and align approaches to the region. They emphasized that ongoing U.S.-Japan cooperation ensures peace and stability based on the rule of law in the Indo-Pacific, which is essential for a safe, prosperous, and secure future for the people of the United States of America and Japan. Both sides committed to enhance alignment on regional priorities, including addressing destabilizing activity by China and North Korea, and strengthening maritime security and law enforcement cooperation. They also explored furthering cooperation across a wide range of fields. The two sides decided to further advance cooperation with like-minded countries. They committed to engage regularly to advance efforts to ensure a free and open Indo-Pacific region. |
Ministry of Foreign Affairs of Japan |
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10/13 |
On October 13, the United States said it stood by its Philippine ally and emphasized their mutual defense treaty after vessels from China and the Philippines clashed amid heightened tensions in the disputed South China Sea.
Earlier, China's Foreign Ministry urged Manila not to challenge Beijing's efforts to "safeguard its territorial sovereignty and maritime rights and interests" after the October 12 incident in the Spratly Islands, in which the Philippines said China deployed water cannon and rammed a Filipino vessel. U.S. State Department spokesperson Tommy Pigott condemned China's "ramming and water cannoning" of a Philippines vessel and said Washington stood with its ally "as they confront China's dangerous actions which undermine regional stability." In a statement, Pigott reaffirmed that Article IV of the 1951 U.S. Philippines Mutual Defense Treaty "extends to armed attacks on Philippine armed forces, public vessels, or aircraft – including those of its Coast Guard – anywhere in the South China Sea."
China and the Philippines have traded accusations over the confrontation near Sandy Cay, a coral reef within the Spratly Islands. The two nations have confronted each other repeatedly in recent years in the South China Sea. Tensions have heightened recently and Lin Jian, a spokesperson for China's foreign ministry, told a regular press briefing the Philippines should immediately stop "violations and provocations."
The State Department said: "China's sweeping territorial and maritime claims in the South China Sea and its increasingly coercive actions to advance them at the expense of its neighbors continue to undermine regional stability and fly in the face of its prior commitments to resolve disputes peacefully." |
|
10/14 |
On October 13, the JMSDF confirmed one Chinese Jangkai II class frigate (hull number 576), one Chinese Luyang III class destroyer (hull number 122) and one Chinese Fuchi class replenishment ship (hull number 889) sailing southeast in the waters 130km northeast of Miyakojima Island (Okinawa Prefecture). These vessels sailed southeast through the waters between Okinawajima Island and Miyakojima Island and navigated to the
Pacific Ocean. |
|
10/14 |
On October 10, the Japan Joint Staff confirmed one Russian IL-20 intelligence gathering aircraft flying from the Sakhalin area over the Sea of Japan and the Sea of Okhotsk. This aircraft then turned back and flew from the Sea of Japan toward the Sakhalin area. The Japan Air Self Defense Force (JASDF) scrambled fighter jets in response to this Russian aircraft.
The Russian IL-20 intelligence gathering aircraft involved in this incident is different from previously identified IL-20 aircraft involved in airspace violations. This particular aircraft has been confirmed by the JASDF for the first time. |
|
10/14 |
On October 14, the JCG announced that a Chinese oceanographic research vessel, Xiang Yang Hong 22, which had been suspected of conducting a oceanographic research in Japan’s EEZ about 385 kilometers west of Amami Oshima Island since October 13, exited the EEZ. The same vessel has been repeatedly observed operating in the surrounding EEZ since late September. |
|
10/15 |
On October 15, according to Japanese government sources, Russia has notified its intention to suspend the right of innocent passage for foreign vessels, including those from Japan, in the waters surrounding the Northern Territories, which Russia illegally occupies. It was also revealed that Russia has announced plans to conduct military exercises around Shikotan Island. The Japanese government lodged a strong protest through diplomatic channels. There are growing concerns that Russia’s repeated assertions of jurisdiction may be aimed at solidifying its illegal occupation as a fait accompli, and the Japanese government is heightening its vigilance.
According to Japan’s Ministry of Foreign Affairs, Russia notified on October 13 that it would suspend the right of innocent passage for foreign warships and other foreign government vessels, excluding those flying the Russian flag. The suspension applies to designated areas around the illegally occupied islands of Shikotan, Kunashiri, the Habomai islets, and Etorofu, as well as waters east of Hokkaido. The Japanese government lodged a protest through diplomatic channels, stating that “the suspension of the right of innocent passage based on Russia’s claims contradicts Japan’s position regarding the Northern Territories.”
Russia also notified in April that it would suspend the right of innocent passage for foreign vessels in the same waters. Under the United Nations Convention on the Law of the Sea (UNCLOS), coastal states must allow foreign ships the right of innocent passage through their territorial waters, as long as such passage does not threaten their security. While coastal states may temporarily suspend this right if it is essential for their national security, the Japanese Ministry of Foreign Affairs stated that Russia has not provided a specific reason for the suspension.
It was also revealed that Russia has notified Japan of its plan to conduct live-fire drills in multiple areas north of Shikotan Island from October 10 to November 1. The Japanese government lodged a protest, stating that “moves to strengthen military capabilities on the Northern Territories are incompatible with Japan’s position and are unacceptable.”
Russia also issued notifications of military exercises in similar areas in August, including on the anniversary of the end of World War II, as well as in June and July. In April, it designated a vast area—including waters near Hokkaido and around the Northern Territories—as a training zone for live-fire drills. The Japanese government lodged protests on each occasion. |
Sankei Shimbun News (Japanese) |
|
10/15 |
On October 15, the JCG announced that it had confirmed a Chinese oceanographic research vessel, Tongji, deploying what appeared to be a wire-like object into the sea within Japan’s EEZ, approximately 215 kilometers west of Tokunoshima Island in Kagoshima Prefecture, on October 14.
The JCG demanded that the vessel halt its activities. While Tongji is believed to have retracted the wire, it remained within Japan’s EEZ as of October 15. |
Jiji Press News (Japanese) |
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