November 28, 2025: China has been deploying three meter and 2 .6 meter in diameter maritime buoys in the South China Sea. Similar buoys are showing up in the Yellow Sea near South Korea. The buoys contain instruments that measure and collect information on wind speed, direction, temperature, humidity, air pressure, atmospheric CO2 partial pressure, visibility, precipitation, waves, currents, seawater temperature, salinity, turbidity, chlorophyll, dissolved oxygen, seawater CO2 partial pressure, and GPS locations of where the data collected as well as when it was collected.

The placement of these buoys in the South China Sea appears to be part of the Chinese effort to assert ownership of the islands and reefs in areas that, according to international law, belong to the Philippines. Similar tactics in the South Korea's Yellow sea are part of a program to take control of the Yellow Sea using tactics and techniques that are working in the South China Sea. Buoys are a new tactic in the Chinese maritime conquest arsenal. China is patient and will continue to develop new tactics and techniques until they wear their opponents down.

China also uses AUVs/Autonomous Undersea Vehicles set loose to collect technical data on the water all the way from the surface to the sea bottom. This data collection is very useful in submarine operations. The AUVs are also called UUVs/Unmanned Underwater Vehicles and they have been getting cheaper, more capable, and more proliferating. These AUVs are silent, very small, and able to operate on their own for up to a year. The first models were two meters long, weighed 59 kgs and operated completely on their own for up to a year collecting valuable information about underwater conditions. What this AUV does is automatically move slowly at 30-70 kilometers a day underwater, collecting data on salinity and temperature and transmitting back via a satellite link every hour or so as the AUV briefly reaches the surface. This data improves the effectiveness of sonars used by friendly forces, making it easier to detect and track enemy submarines. That’s because the speed of sound travelling through water varies acco

The U.S. Navy currently has over 2,000 of these AUVs in service or on order and plans to keep increasing this robotic ASW fleet as long as they keep demonstrating they can do the job. UAVs replace many of the ocean survey ships long used for this kind of work. The survey ships take temperature and salinity readings from instruments deployed from the ship as well as a global network of several thousand research buoys. Unlike the survey ships, the AUVs can be deployed in areas where hostile subs are believed to be operating and be kept at it if needed. If successful in regular use, larger versions are planned, equipped with more sensors and longer duration.

China already has survey ships in service as well as a growing network of buoys. China will be deploying its autonomous AUVs throughout the Western Pacific and Indian Ocean, along with buoys. The AUVs and buoys will be serviced by the expanding Chinese fleet that is seen more frequently throughout the Pacific and Indian Oceans. China has already captured or stolen, if classified, a lot of data similar to what American systems collected over the decades and is using that to enhance its own databases.

For the moment this new network concentrates on the South China Sea but will also include land-based data processing and fusion combining data from different sensors in one of the Paracel Islands in the South China Sea, another in South China’s Guangdong province and third somewhere in South Asia where it will share data with other nations. The data fusion centers will also include material collected by warships and commercial ships and aircraft. China also plans to make some of this data available to everyone as a contribution to safe operation of maritime commerce and fishing.