Since October 2023, ships from Russia's sanctions-evading "shadow fleet" have damaged 11 pieces of undersea infrastructure in the Baltic Sea - communication cables and pipelines vital to the region's energy and digital connectivity. The Polish Institute of International Affairs documented the growing scale of this threat in its March 2026 report on Baltic Sea Region security, noting that the number of incidents continues to rise.
As "Hvylya" reports, citing the PISM analysis, the tactic of dragging anchors along the seabed to damage infrastructure was "adopted from China, which uses it against Taiwan." The first major incident came in October 2023, when the Chinese container ship Newnew Polar Bear - operated by a Russian crew - damaged the Balticconnector gas pipeline and a fiber optic cable connecting Sweden and Estonia. The vessel then fled the Baltic with Russian icebreaker support.
The incidents have continued. In November 2024, the Chinese ship Yi Peng 3 damaged fiber optic cables between Finland and Germany and between Sweden and Lithuania. One of the most recent cases involved the Estlink 2 power cable between Finland and Estonia, which led to the Finnish Navy detaining the crew of the tanker Eagle S. Each incident carries repair costs estimated between $645,000 and $1.29 million, on top of financial losses from disrupted energy supplies.
The "shadow fleet" itself consists of aging tankers used to circumvent Western sanctions on Russian oil exports. These vessels "do not have full P&I insurance coverage, or only have minimal coverage," feature opaque ownership structures, frequently change flags, and manipulate their Automatic Identification Systems to conceal their positions. The fleet handles 70 to 80 percent of Russia's seaborne crude and petroleum product exports, with more than 40 percent of that cargo transiting the Baltic Sea.
The PISM report highlights a dual threat: beyond direct infrastructure sabotage, these poorly maintained vessels pose severe environmental risks to the Baltic - a shallow, semi-enclosed basin with slow water exchange and high pollution vulnerability. The Baltic Sea's surface temperature is already rising at 0.38 degrees Celsius per decade, making it a "hotspot of rapid warming" where any oil spill would cause disproportionate ecological damage.
The researchers recommend that Baltic states pursue "coherent strategic signalling" toward Russia, making clear that actions targeting critical infrastructure will carry tangible political, economic, and military costs. They call for expanded monitoring capabilities, common procedures for detaining and inspecting suspicious vessels, and tightened Western energy sanctions specifically targeting the shadow fleet's operations.
Also read: Dismantle the Shadow Fleet in Three Months: Zeihan Outlines a Scenario for Crushing Kremlin Revenue.