China has erected a fixed platform in the provisional waters of the Yellow Sea, repurposing an offshore drilling rig into a large-scale structure. Satellite and drone imagery reveal a massive steel installation anchored to the seabed, spanning 100 meters in width, 80 meters in length, and rising 50 meters high. The platform is outfitted with a helipad and resembles an artificial island—mirroring the strategic construction China carried out in the South China Sea.
Since 2001, South Korea and China have observed a maritime agreement designating a provisional zone in the Yellow Sea, where a maritime boundary remains undefined. Under this agreement, both sides pledged to restrict all activity in the zone aside from fishing. In 2024, however, China deployed two large mobile platforms to the area, labeling them fish farms. It claimed the structures did not breach the agreement, citing their fishery-related purpose. China is now making the same argument for its newly installed fixed platform, calling it a “management facility” for the fish farms.
Critics, however, question the rationale behind establishing a “management facility” of such scale—larger than a soccer field—in open waters. They argue that the true objective is evident: Beijing appears to be employing the same incremental tactics it used in the South China Sea to assert de facto control over contested maritime areas.
More than a decade ago, China constructed seven artificial islands in the South China Sea by cementing over reefs, installing airstrips, and deploying military personnel. These installations were gradually expanded, while neighboring countries were barred from access. In 2016, the Permanent Court of Arbitration ruled against China in a maritime sovereignty dispute, but Beijing dismissed the verdict. Today, it claims more than 85 percent of the South China Sea—an expanse larger than the Mediterranean Sea—as its territorial waters. China’s strategy has been systematic: plant a stake in disputed waters, then advance incrementally.
In 2014, a Chinese oil rig was stationed near Vietnamese waters, prompting Vietnamese fishing vessels to confront it. Chinese escort ships responded by ramming and sinking the Vietnamese boats. Beijing is known to operate a maritime militia—nominally civilian vessels that function as paramilitary agents on behalf of the navy in disputed areas. These ships are often armed and have been involved in direct confrontations. In February, when a South Korean maritime research vessel approached the fixed structure in the Yellow Sea, three Chinese civilian boats intercepted it in an aggressive maneuver. One Chinese crew member was reportedly seen brandishing a knife. With a helipad already in place, the platform could be converted into a military outpost at any time.
China’s effort to expand its control over the Yellow Sea—what some observers have described as “South China Sea-style tactics”—began more than a decade ago. Chinese patrol vessels entered waters near Baengnyeongdo Island, close to the 124th meridian east longitude, and warned South Korean naval ships not to cross. Now, China appears to be escalating its strategy through artificial island-style construction. Unlike the floating fish farms, the newly established fixed platform represents a fundamental shift in posture.
In matters of territorial sovereignty and national interest, there is no room for political division. It is encouraging that both the People Power Party (PPP) and the Democratic Party (DP) have spoken with one voice, condemning China’s actions as a violation of South Korea’s sovereignty. The two parties must now coordinate a unified and robust response.
To avoid repeating the missteps that led to diminished territorial claims in the South China Sea, South Korea must respond in kind to China’s provocations. If Beijing continues to ignore bilateral agreements, Seoul should invoke the principle of reciprocity and consider deploying its own large-scale installations, including drilling rigs and fishery structures. The government must begin by securing the necessary funding and waiving preliminary feasibility studies to accelerate proportional countermeasures.
