Shadow Fleet Keeps Strait of Hormuz Open Despite International Sanctions
The Strait of Hormuz is effectively closed. Since the beginning of the conflict involving the United States, Israel and Iran on Feb. 28, 2026, oil tanker traffic through the world’s most critical oil shipping choke point has collapsed, dropping by more than 90%. However, some vessels have found ways to continue operating, ignoring international restrictions on trade with certain countries.
These ships are part of a shadow fleet that operates outside the rules. In maritime circles, they are referred to as “shadow tankers.” They exist because the world’s oceans aren’t governed the same way the land is. On land, armed personnel closely monitor carefully delineated borders, seeking to force everyone to follow clear rules. But at sea, regulation is almost the opposite. The system that governs international shipping is, at its foundation, voluntary.
Trust and Voluntary Regulation
The tracking of ships is voluntary. The International Convention for the Safety of Life at Sea – signed by 167 countries – requires almost every commercial vessel to carry a radio transponder that broadcasts the ship’s identity, position, speed, and heading to port authorities, coast guards, and commercial tracking networks. However, there is no physical mechanism preventing a crew from switching it off or broadcasting a false position.
When a vessel turns off its transponder and goes dark, it doesn’t trigger an alarm at some global maritime headquarters. There is no such headquarters. The ship simply disappears from the map. Every map. National jurisdiction is a matter of preference, not law. Every vessel sails under the flag of a nation, and that nation is theoretically responsible for regulating and inspecting it.
Shell Companies and Flags of Convenience
A ship owned by a shell company in the United Arab Emirates can register under the flag of Cameroon, Palau, or Liberia, or any country that may lack the resources or the incentive to conduct real inspections. Even landlocked Mongolia has a registry of oceangoing ships flying its flag. When a vessel comes under scrutiny from port inspectors or coast guards, it can simply reregister under a different flag.
Insurance and Enforcement
Mainstream insurers, mostly based in London, require vessels to meet safety standards, carry proper documentation, and comply with international trade sanctions. A ship without insurance coverage cannot easily enter major ports or secure cargo contracts with reputable firms. Those restrictions are precisely what froze so many law-abiding ships in the Persian Gulf when war broke out.
However, companies can avoid those rules, too. Two-thirds of ships carrying Russian oil – the tanker fleet that represents one vessel in a larger network of ships used to circumvent international sanctions against Russia – operate outside these regulations. They have found ways to secure insurance coverage from smaller, less reputable firms or by registering under flags of convenience.
Despite the challenges and risks involved, some vessels continue to transit the strait, ignoring international restrictions on trade with certain countries. The shadow fleet is a testament to the flexibility and adaptability of the maritime industry, as well as its ability to find ways around regulations.
Original Article: Why shadow tankers are the only ships still moving through the Strait of Hormuz — Theconversation