After aggressive posturing in the South China Sea, China is upping the ante in the Yellow Sea, following the building of a gigantic steel rig.

This has been a bone of contention between South Korea and China. The Coast Guards of the two countries recently had a standoff after Korean ships wanted to investigate the steel structure.

South Korean news agency Yonhap quoted diplomatic sources as saying that the two coast guards had engaged in a two-hour-long standoff. The confrontation took place on the afternoon of February 26 in the Provisional Maritime Zone (PMZ) near Socotra Rock, southwest of South Korea’s Jeju Island.

The PMZ is a jointly managed stretch of the Yellow Sea, also known in Korea as the West Sea, where the exclusive economic zones (EEZs) of China and South Korea overlap.

In an uncanny similarity to its strategy against the Philippines Coast Guard, the Chinese coast guard vessels and civilian boats blocked the South Korean research ship Onnuri, which was there at the behest of the South Korean government to conduct a survey of the structure.

According to South Korean media, in response, Seoul dispatched a coast guard vessel to the scene, resulting in a two-hour standoff. South Korea contended its inspection was legitimate, whereas the Chinese side claimed that the structure was an aquafarm and asked the Korean vessel to leave.

South Korea had reportedly summoned an official from the Chinese Embassy in Seoul to lodge a protest over the incident.

Latest satellite images indicate that China has installed several large steel platforms in the PMZ. The PMZ was established under a 2000 agreement, which allows fishing and navigation in the disputed region until the maritime boundary issue is resolved.

This differs from the EEZ, which extends 200 nautical miles from the coast and grants the claimant country exclusive rights to access its underwater resources and fishing grounds, as per international maritime law.

Shen Lan 2 Hao (or Deep Blue 2) is a 71.5-meter-tall underwater marine cage deployed by China into the PMZ for salmon aquaculture. The massive cage and the jack-up support rig sparked concern in South Korea. The Korean government asserts its right to inspect the structure under the 2001 Korea-China Fisheries Agreement.

South Korea alleges that the structure was placed without prior notification or consent. On earlier occasions, China had installed platforms in the region, only to have them removed following protests from Seoul. However, the latest installation, featuring three long legs that can be lowered to the sea floor for stability, signals China’s beefing up of its presence in the region.

Move To Grab Territory?

The overlapping areas of EEZs between China and South Korea in the Yellow Sea are believed to be rich in natural resources, including oil. In pursuance of cementing its claims, China has been installing artificial structures.

Ray Powell, the Director of SeaLight and Project Lead for Project Myoushu at Stanford University’s Gordian Knot Center for National Security Innovation, examined the images from Planet Labs. According to him, the rig measures approximately 108 meters long (from helipad to its opposite tower) and 82 meters broad.

Based on SeaLight’s analysis, “this rig was first deployed in October 2022. The new rig replaced a smaller rig that was sent out at least two years before to join Shen Lan 2 Hao’s own smaller predecessor, Shen Lan 1 Hao, which was first deployed in 2018 to much fanfare.”

Sealight analysis sheds light on the impasse in the East China Sea. The Qingdao-based China Coast Guard (CCG) 6402, along with the patrolling CCG 6305 and three civilian-crewed rubber boats, blocked the path of the Korean research vessel. Chinese civilians aboard the rubber boats were reportedly armed with knives and shouted demands to leave.

China claims Shen Lan 2 Hao heralds a new era in sustainable aquaculture. It is operated by the state-backed Shandong Marine Group and features automated feeding systems, underwater imaging, and remote-control capabilities, enabling salmon farming in 9,000 cubic meters of caged water. Disregarding the 2001 agreement, Beijing claims the structure is located within its Exclusive Economic Zone (EEZ).

However, the Socotra Rock, known as Ieodo in South Korea and Suyan Islet in China, where the standoff took place, is a submerged rock formation that falls within the overlapping EEZ claims between the two countries. In fact, in 2003, when South Korea set up the Ieodo Ocean Research Centre, Beijing described the move as “unilateral” and “illegal.”

According to Powell, “A more cynical view is that this is an early step in bringing a South China Sea-style gray zone campaign of ‘salami slicing’ to the Yellow Sea. In this view, the incremental deployment of rigs of increasing size into the PMZ reflects a recognizable pattern of testing rival states’ resolve with ostensibly civilian and coast guard presence while avoiding overt militarization.”

The former USAF veteran, Powell, contends that China’s civil-military fusion keeps the door open for non-salmon harvesting activities, such as intelligence collection, close to its giant support rig. There is no difference between the Chinese Navy, Coast Guard, and militia. It is all under the aegis of national maritime security. They just have different roles. It is a ‘might be the right’ kind of setup. That is why like-minded countries are coming together to establish a rule-based order.

China’s distant-water fishing fleet has been suspected of intelligence gathering and is the vanguard of China’s “Gray Zone Tactics.”