China Coast Guard patrols near oil and gas projects in the South China Sea have triggered responses from Vietnamese law enforcement and the Malaysian navy in two separate incidents over the last month.

Contested Patrols at Nam Con Son and Vanguard Bank

Chinese and Vietnamese law enforcement vessels had an extremely close encounter on March 25 near Vanguard Bank, as reported by Radio Free Asia along with Reuters and others. A look into historical automatic identification system (AIS) data from commercial provider MarineTraffic shows that while this encounter was unusually dangerous, interactions between Chinese and Vietnamese vessels in the area have been a regular occurrence in recent months.

On March 25, Vietnam Fisheries Surveillance (Kiem Ngu) 278 pursued China Coast Guard (CCG) 5205 as the latter patrolled oil and gas wells in the Nam Con Son basin, a critical area for Vietnamese offshore energy that supplies an estimated 13.5 percent of the country’s power needs.

CCG 5205 visited Chim Sao field in block 12W, Lan Tay field in block 06-1, Moc Tinh and Hai Thach fields in blocks 05-3 and 05-2, and Lan Do field in block 06-1, slowing but not stopping at each. Then it left the area heading southwest toward Vanguard Bank. When CCG 5205 stopped 13 nautical miles south of Vanguard Bank, Kiem Ngu 278 approached and the two maneuvered at extremely close distances, with AIS indicating the two ships may have approached to within 10 meters. Kiem Ngu 278 then followed the CCG vessel another 30 nautical miles south and had a similarly close encounter before the 5205 finally left the area, heading southwest into Malaysia’s exclusive economic zone.

A review of historical AIS data reveals that CCG vessels have been making regular passes through Vietnamese oil and gas concessions at Nam Con Son since at least last fall, with some evidence of occasional pass-throughs dating back as early as May 2022.

Recent China Coast Guard Patrols Through Nam Con Son
China Coast Guard Ship Patrol Dates Vietnamese Tailing Vessels
CCG 5304 September 22, 30; October 7, 17, 20, 27; November 3 Kiem Ngu 268, 263
CCG 5402 November 6, 10, 16, 30; December 1, 7, 16 Kiem Ngu 263, 264
CCG 5901 January 8, 13, 23 VCG 8005, Kiem Ngu 264
CCG 5302 February 5, 14 Kiem Ngu 263
CCG 5205 March 25 Kiem Ngu 278

With few exceptions, each Chinese ship was shadowed by either the Kiem Ngu or Vietnam Coast Guard (VCG) as it passed through Nam Con Son and when it left the area. But though Vietnamese vessels were sometimes seen approaching within a few hundred meters, AIS data suggests that there hadn’t before been an encounter as close as that on March 25.

The China Coast Guard 5304 followed by Kiem Ngu vessels at Vanguard Bank on September 29 and October 24; the China Coast Guard 5901 passing through Nam Con Son on January 23 followed by the Kiem Ngu 264

This signals a break from past behavior. The CCG has been regularly patrolling Vanguard Bank since 2020 but had previously approached the Nam Con Son oil and gas fields only occasionally to make targeted challenges to specific development projects. It now appears that Nam Con Son has been added to the regular route of CCG vessels assigned to patrol duty at Vanguard. This is similar to the pattern off Malaysia’s Sarawak State, where CCG vessels stationed at Luconia Shoals consistently patrol nearby Malaysian oil and gas projects.

The China Coast Guard at Kasawari

Malaysia’s Kasawari gas project has been no stranger to attention from the CCG, but tensions appear to be building. Satellite imagery and AIS data show that CCG 5901 has been operating near construction at Kasawari for the last month, drawing a response from the Royal Malaysian Navy. The world’s largest coastguard vessel, the 12,000-ton 5901 last made headlines in January when it appeared near Indonesia’s Tuna oil and gas project after Jakarta announced a $3 billion plan to develop the block.

Kasawari, slated to begin production this year, lies 25 nautical miles to the southeast of Luconia Shoals, a regular location of CCG patrols. Notices from Malaysia’s Marine Department indicate the transportation of a jacket structure for the Kasawari Central Processing Platform began on February 24, with construction and installation beginning on March 8 and scheduled to last until April 30.

The 5901 arrived at Luconia Shoals on February 17 and quickly took notice of operations at Kasawari, with AIS data showing it approached to within 7 nautical miles on February 18, and then to within 1.5 nautical miles on March 11-12 and 17-19. Its AIS signal was intermittent during the period, meaning it likely spent even more time at Kasawari, and possibly at closer distances. During a gap in its AIS signal on March 20, for example, it was captured on satellite imagery observing operations east of the platform:

It was around this time that Kuala Lumpur took notice. The Royal Malaysian Navy’s KD Badik, en route from peninsular Malaysia to Sabah, stopped at Kasawari on March 19. The Badik is one of four Keris-class littoral mission ships that Malaysia purchased from China in a 2016 deal. Available AIS data suggests it stayed west of the platform to avoid direct contact with the 5901 on the eastern side, but its signal was also intermittent, meaning that closer encounters could have taken place.

The KD Badik last broadcast AIS from Kasawari on March 22, with its signal appearing again once it had returned to shore at Kota Kinabalu on March 24. As of publishing, the 5901 remains on patrol at Luconia Breakers.

In an early March report on the development of Vietnam’s Nam Con Son, Malaysia’s Kasawari, and Indonesia’s Tuna projects, AMTI warned that oil and gas development could reemerge as a flashpoint in the South China Sea this year. Evidence to that effect continues to mount.