According to www.seatrade-maritime.com, the so-called ‘dark fleet’ — vessels engaged in sanctioned oil trade while evading detection — now comprises 12% of the global tanker fleet, up from earlier estimates and driven by tightening US sanctions and expanded vessel listings.
Sanctions Waiver and Visibility Shift
A recent US sanctions waiver for Iranian crude exports has altered operational patterns: Iranian tankers en route to Asia are now sailing with active AIS transponders, abandoning previous ‘dark’ navigation tactics. This marks a sharp departure from behavior before 28 February, when vessels routinely disabled tracking to obscure origins and destinations. The shift coincides with heightened enforcement — including US Navy Hellfire missile strikes on international tankers in the Gulf of Oman, one of which killed three Indian seafarers.
Scale and Composition of the Dark Fleet
Veson’s Matthew Freeman, VP Valuation & Analytics, confirms the dark fleet continues expanding for two primary reasons. First, sanctions are intensifying: around one hundred vessels have been added to the US Treasury’s Office of Foreign Assets Control (OFAC) sanctions list this year alone. Second, previously legitimate operators enter the dark fleet only after beginning sanctioned cargo trades — meaning vessel ownership alone does not indicate status, but operational intent does.
The exact size remains contested. While the OFAC sanctions list suggests the dark fleet represents 8% of the global tanker fleet, Veson’s broader methodology — incorporating vessels suspected of carrying sanctioned cargoes — places the figure at 12%. This expansion follows the rapid growth triggered by sanctions on Russian oil and gas after the 2022 invasion of Ukraine.
Operational Hotspots and Tactics
Ship-to-ship (STS) transfers remain central to dark fleet logistics, particularly in Malaysia’s Eastern Outer Port Limits (EOPL) anchorage. Satellite imagery and maritime monitoring confirm ongoing STS activity there involving Iranian tankers — even as those vessels now broadcast AIS signals openly. This hybrid approach — transparency on location combined with opacity on cargo origin, destination, and beneficial ownership — complicates regulatory oversight and port state control.
The Strait of Hormuz has also become a flashpoint: Iran declared it closed on 22 June 2026, heightening regional tension and raising insurance and routing costs for commercial shippers. Meanwhile, the flotilla of Iranian tankers heading toward Asian markets operates under the newly granted waiver — yet still relies on established shadow infrastructure, including third-country flag registries and opaque corporate structures.
Industry Implications for Supply Chain Professionals
For supply chain professionals managing energy logistics, the dark fleet’s growth introduces layered risk: compliance exposure, voyage delays due to increased naval interdiction or port denials, and volatility in freight rate benchmarks. Unlike traditional shipping disruptions, this threat stems not from capacity shortages or weather, but from deliberate, state-enabled circumvention of multilateral sanctions regimes. Monitoring tools must now integrate AIS anomaly detection, OFAC list cross-referencing, and real-time vessel ownership mapping — capabilities increasingly embedded in platforms like those offered by Veson.
“The dark fleet is still increasing for two reasons. The first reason was sanctions were tightening and this was seeing more ships being added to sanctions lists.” — Matthew Freeman, VP Valuation & Analytics, Veson
Practitioners report rising due diligence burdens — especially for charterers, insurers, and terminal operators verifying cargo provenance and financial flows. The 12% penetration rate means nearly one in eight tankers globally may be operating outside standard compliance frameworks, demanding proactive, data-driven verification beyond traditional documentation checks.
Source: Seatrade Maritime
Compiled from international media by the SCI.AI editorial team.
