China’s coast guard presence in the South China Sea is more robust than ever. An analysis of automatic identification system (AIS) data from commercial provider MarineTraffic shows that the China Coast Guard (CCG) maintained near-daily patrols at key features across the South China Sea in 2022. Together with the ubiquitous presence of its maritime militia, China’s constant coast guard patrols show Beijing’s determination to assert control over the vast maritime zone within its claimed nine-dash line.

China Coast Guard Patrols in the South China Sea

AMTI analyzed AIS data from the year 2022 across the five features most frequented by Chinese patrols: Second Thomas Shoal, Luconia Shoals, Scarborough Shoal, Vanguard Bank, and Thitu Island. Comparison with data from 2020 shows that the number of calendar days that a CCG vessel patrolled near these features increased across the board.

The number of days the CCG patrolled at Vanguard Bank, a major site of Vietnamese oil and gas development that has seen standoffs between Chinese and Vietnamese law enforcement in years past, more than doubled, increasing from 142 days in 2020 to 310 days in 2022. Days patrolled at Second Thomas Shoal, where the Philippines maintains a precarious garrison aboard the BRP Sierra Madre, increased from 232 days to 279; those at Luconia Shoals, near important Malaysian oil and gas operations, from 279 to 316; and at Scarborough Shoal, traditionally fished and administered by the Philippines, from 287 to 344. Data on the reefs surrounding Philippine-held Thitu Island was not collected in previous analyses, but CCG vessels were on site 208 days over the past year. At some features, especially Scarborough Shoal, multiple CCG vessels were present simultaneously. Observed patrols across all five features amounted to 1,703 ship-days in total.

The incomplete nature of AIS data means that these numbers are likely even higher. Some CCG vessels are not observable on commercial AIS platforms, either because their AIS transceivers are disabled or are not detectable by satellite AIS receivers. In other cases, CCG vessels have been observed broadcasting incomplete or erroneous AIS information. One such case involved a vessel broadcasting near Thitu Island under the name “Dujuae” and identifying itself as a cargo vessel. Satellite imagery, however, revealed that the ship was actually a 101-meter Zhaojun-class (Type 718B) coast guard cutter:

China Coast Guard vessel broadcasting as “Dujuae,” Thitu Island, February 19, 2022

The behavior of CCG vessels observed on patrol in 2022 was similar to that of years past. But AIS data tells only part of the story of the CCG’s influence in the Spratly Islands and its friction with Southeast Asian law enforcement, which took new forms in 2022. Oil and gas standoffs, a recurring feature of the last three years prior, were not as prominent in 2022, likely due to the success of the previous CCG harassment. For instance, China convinced the Philippines to shut down renewed exploration of Reed Bank in April when the CCG 5203 shadowed a contracted survey vessel. Indonesia may become an exception to this general retreat of Southeast Asian claimants from new oil and gas exploration, with Jakarta in January 2023 committing to develop its Tuna gas block despite previous CCG harassment.

The CCG also worked with maritime militia at Second Thomas Shoal to obstruct resupply missions to Philippine marines stationed on the shoal multiple times throughout 2022. And in another publicized incident, Chinese and Philippine law enforcement came face to face at Thitu Island in November when CCG cut the tow line of a Philippine vessel removing Chinese rocket debris from waters west of the island. As Southeast Asian claimants continue to operate in the Spratly Islands in 2023, the constant presence of China’s coast guard and maritime militia makes future confrontations all but inevitable.