Satellite imagery analysis shows that China’s maritime militia deployed to the South China Sea in record numbers in 2024.  But in contrast to recent years, a majority of ships spent most of their days anchored at China’s military outposts rather than at unoccupied reefs where they might pretend to fish. This suggests Chinese authorities are not pressuring vessel owners to maintain the crumbling façade of the militia as a legitimate fishing fleet, and as a result the vessels are prioritizing the easier resupply, safety, and comfort available when they are within the lagoons of China’s island bases.

Methodology 

China’s maritime militia is the largest fleet of ships operating in the disputed waters of the South China Sea. But unlike the China Coast Guard, most militia cannot be observed on satellite-based automatic identification system platforms. To track the militia’s presence across disputed waters, AMTI examined Planet Labs satellite imagery for the calendar year 2024 at 11 features in the South China Sea that militia ships are known to frequent. Militia vessels were counted in imagery an average of four times per month at each feature, and data on days between observations was interpolated linearly between the two nearest observations to enable comparison across features. 

Most of these vessels are members of China’s Spratly Backbone Fishing Fleet, the civilian component of the militia which is numerically larger than the professional component AMTI profiled in December. Although by regulation, these vessels can be as small as 35 meters in length, only ships falling between 45 and 65 meters were counted for the purposes of this study. This is the most common length for Chinese militia trawlers and a range rarely seen in other vessels active in disputed waters, such as China Coast Guard or fishing vessels of other coastal states.