Why Chinese Research Vessels Hit a Record Around Taiwan

Taiwan's Coast Guard Administration has disclosed data showing that the number of Chinese coast guard and scientific research vessels operating around Taiwan reached a record in July. The monthly counts cited by the agency included 55 in June and 30 in May; by comparison, July last year was 58. The total excludes the Chinese navy warships that now operate near Taiwan almost daily, meaning the research and enforcement fleet is an additional layer of maritime pressure.

Beijing claims Taiwan and its adjacent waters as part of Chinese territory, and has increasingly used law-enforcement and civilian-coded ships to assert that claim short of open conflict. Taiwan's coast guard said it is monitoring and tracking 41 Chinese oceanographic research vessels that have operated in nearby waters, out of a Chinese fleet of more than 120 such ships.

This month, China also announced unilateral traffic control measures in the Taiwan Strait as Typhoon Dolphin approached, a further example of administrative pressure layered on top of the vessel deployments. Taiwan coast guard officials said the situation is becoming more serious, with a particularly notable increase in July.

The concern is not simply the number of ships. Taiwan's coast guard assessed that Chinese activity included sample collection and seabed surveys that could contribute to a Chinese anti-submarine-warfare database. Analysts quoted in the report said the new element is the unprecedented scale of operations around Taiwan.

Submarine-Warfare Data, Salami Tactics and Undersea Cables

China's Anti-Submarine-Warfare Data Campaign

Taiwan's Coast Guard Administration believes the seabed surveys and sampling are not purely scientific. In its assessment, the activity could contribute to a Chinese database for anti-submarine warfare. A Taiwan security official, speaking in a personal capacity, said such bathymetric and oceanographic data would be highly useful to Chinese navy units operating in those waters in a contingency, particularly for hunting submarines.

Gray-Zone and Salami Tactics Around Taiwan

Officials and experts describe the deployments as a gray-zone campaign: use non-military ships to assert jurisdiction and apply pressure while stopping short of war. One Taiwan security official called the approach salami tactics, meaning Beijing advances through small, incremental actions rather than a single decisive move. The Chinese announcement of traffic-control measures in the Taiwan Strait during Typhoon Dolphin fits that pattern because it tests administrative control without firing a shot.

Xiangyanghong 03 and the Undersea-Cable Question

Satellite-imagery and ship-signal analysis firm ingeniSPACE, through COO Jason Wang, said the Chinese research vessel Xiangyanghong 03 operated this month inside Taiwan's and Japan's exclusive economic zones, crossing the Ryukyu Trench and the eastern Taiwan trench and passing over undersea communication cables. Wang said the likely aims are to collect current oceanographic data for anti-submarine operations and to deter similar activity by US and allied vessels. Even if the data is used only for oceanography, the location of the survey lines over cable routes makes the operations relevant to seabed-infrastructure security.

Analyst Martinson, cited in the report, said the tactic itself is not new; what is new is that the scale around Taiwan has reached an unprecedented level.

What Taiwan, Japan and Allied Maritime Agencies Should Track Next

  • Treat Chinese research vessels as dual-use intelligence assets. Taiwan's coast guard is already tracking 41 hulls, and the Xiangyanghong 03 was tracked over the Ryukyu and eastern Taiwan trenches rather than only in open water.
  • Give priority to undersea-cable corridors. The Xiangyanghong 03's course crossed seabed communication-cable routes. Surveys along those paths can generate the seafloor detail relevant to future anti-submarine operations or cable interference.
  • Prepare for administrative assertions during weather events. China used Typhoon Dolphin as the occasion to announce traffic-control measures in the Taiwan Strait; Taiwan and Japan should have clear maritime-safety counter-notifications ready for ordinary shipping.
  • Keep PLA Navy patrols separate from the research and enforcement count. The record July figure excludes Chinese navy warships, so public monthly counts understate total Chinese maritime presence around Taiwan and should be integrated with satellite AIS and radio-frequency tracking.