The Week in Focus Three developments this week carry direct implications for maritime operations worldwide: the U.S. announcing a blockade on sanctioned Venezuelan tankers as Caribbean dark fleet activity surges 95% year-on-year; Ukraine expanding drone strikes against Russia’s sanctions-evasion tankers in the Black Sea; and escalating air-sea confrontations in the East China Sea prompting a...
At a Glance From Monitoring to Intervention The dark fleet – tankers engaging in dark activities while moving sanctioned oil, cycling through false flags, and obscuring ownership – has continued to expand, reaching more than 1,900 vessels by the end of Q3. Governments had visibility into this activity. What was less consistent was how that...
Maritime Defense Weekly: Venezuela Blockade, Dark Fleet Under Fire
What’s inside?
The Week in Focus
Three developments this week carry direct implications for maritime operations worldwide: the U.S. announcing a blockade on sanctioned Venezuelan tankers as Caribbean dark fleet activity surges 95% year-on-year; Ukraine expanding drone strikes against Russia’s sanctions-evasion tankers in the Black Sea; and escalating air-sea confrontations in the East China Sea prompting a U.S.-Japan bomber response.
Western Hemisphere: Venezuela on Notice
Blockade Announced, Dark Fleet Under Attack
The Administration has announced a blockade on sanctioned tankers entering or leaving Venezuela.
“Venezuela is completely surrounded by the largest Armada ever assembled in the History of South America. It will only get bigger, and the shock to them will be like nothing they have ever seen before — Until such time as they return to the United States of America all of the… pic.twitter.com/WWQwJfcplD
The move follows the seizure of the sanctioned oil tanker Skipper (IMO 9304667) off the Venezuelan coast, a very large crude carrier that fits the dark fleet profile precisely: falsely flagged to Guyana, U.S.-sanctioned since November 2022, no known insurance or recognized classification society, and a protracted history of Iran-Venezuela trading with multiple instances of AIS spoofing and deceptive ship-to-ship transfers.
Windward Remote Sensing Intelligence indicates Skipper‘s AIS reappeared on December 10 some 360 nautical miles from its last spoofed signal off Venezuela — confirming the vessel was not where its tracking system claimed.
Sanctions Pressure Intensifies
On December 11, OFAC sanctioned six companies owning six VLCCs engaged in Venezuelan oil trade: White Crane, Kiara M, H.Constance, Lattafa, Monique, and Tamia. According to OFAC, four manipulated AIS signals in May, June, September, and October. Three called at Lome, Togo — a known STS transshipment hub and spoofing location. Notably, four had Western insurance, indicating sanctions evasion networks penetrating mainstream maritime services.
All tankers spoofing their location while calling Venezuela now face heightened U.S. sanctions risk.
Caribbean Dark Fleet Activity Surging
Tankers associated with Iran, Venezuela, or Russia conducted over 130 area visits to the Caribbean Sea in the past 30 days, involving 116 vessels:
19 vessels are sanctioned.
81 are classified high-risk.
14 fly fraudulent flags.
Area visits up 95% year-on-year.
A cyberattack on PDVSA systems on December 14-15 disrupted loading operations. Some tankers are already declining Venezuela business. False-flag vessels face the highest interdiction risk under Article 110 of UNCLOS, which permits boarding of ships without nationality.
Russia-Venezuela Nexus Deepening
Russia is now supplying PDVSA with diluent after U.S. shipments stopped. Venezuela has imported three times as much Russian naphtha this year as in all of 2024. Russian dark fleet tanker Seahorse (IMO 9266750) arrived at Venezuela in late November after its route was disrupted by USS Stockdale as it sailed from Cuba.
The question for policymakers: will the U.S. curtail delivery of Russian energy commodities to Venezuela as tensions with both countries escalate?
Global Maritime Implications
Escalation could affect:
Global oil markets: Venezuelan crude exports face potential full disruption; watch for price volatility and supply reallocation.
Caribbean shipping routes: Blockade operations will increase naval traffic density, affecting transit times and insurance premiums.
Sanctions enforcement: Vessel owners and flag states should urgently review exposure to sanctioned Venezuelan trade.
Regional stability: Spillover risk for neighboring maritime zones (Colombia, Trinidad and Tobago, Guyana).
Black Sea: Ukraine Targets Dark Fleet
Ukraine has adopted a new strategy of targeting Russia’s dark fleet directly with drone strikes:
Dec 10: Sea Baby drone attack on Dashan (IMO 9299666).
Dec 15: Ukraine claims drone submarine strike at Novorossiysk (denied by Russia).
Targeted tankers were sanctioned, flagless and stateless, falsely claiming to fly the flag of Gambia — part of 72 vessels deleted by Gambia’s maritime authority in November. This invalidates their class and insurance.
Falsely flagged tankers in Black Sea at risk of Ukraine drone attack. Source: Windward Maritime AI™ Platform
Bulgaria’s Maritime Administration successfully towed the previously attacked Kairos to Burgas Bay on December 15, but stated costs incurred by the state would be billed to the shipowner before the vessel can leave Bulgarian waters — raising unresolved questions about who pays for salvage and repair of stateless, uninsured vessels.
Indo-Pacific: East China Sea Heats Up
On December 7, Japan reported Chinese fighter jets locked fire-control radar onto Japanese military aircraft over the East China Sea. Beijing called Japan the aggressor. Two days later, China conducted a joint air patrol with Russia, forcing Japan to scramble interceptors.
Washington responded on December 11: U.S. nuclear-capable bombers flew alongside Japanese F-35s and F-15s over the Sea of Japan — a coordinated show of force signaling allied commitment to keeping these waters open.
Global Maritime Implications
The East China Sea sits astride some of the world’s busiest shipping lanes, connecting Northeast Asian manufacturing to global markets. Sustained escalation would affect commercial shipping, complicate freedom of navigation, and raise insurance and routing costs. Governments with trade exposure to Northeast Asia should monitor this theater closely.
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