Russian “Dark Fleet” Exploits AIS System to Evade Sanctions
The Financial Times reported in October an increase in spoofing activities by some Russian oil tankers subject to international sanctions, known as the “dark fleet.” Some of these vessels have successfully appeared simultaneously in two different locations, sometimes hundreds of kilometers apart. A notable example is the Russian oil tanker “Pirop,” which on August 27 transmitted positions approximately 800 kilometers apart. This technique, known as spoofing, involves falsifying information transmitted through the Automatic Identification System (AIS).
Spoofing and AIS Manipulation
The phenomenon is not new in its nature but appears to have reached a level of coordination that is unusual. It has also been observed that over 80 vessels have reflagged themselves under the Russian Federation’s flag between July and September 2026. This trend is significant, considering that European and British authorities have imposed sanctions on nearly 700 oil tankers involved in transporting Russian oil and gas over the past two and a half years.
To understand the scope of this phenomenon, it is essential to first consider how the AIS system works. The system installed on board vessels periodically transmits information about their position, route, speed, and identity. Signals are received by coastal stations and other units within radio range and, at sea, can be captured by satellites equipped with specialized receivers. Manipulating these data poses a significant threat to navigation safety, as well as facilitating illicit activities.
Temporary AIS Disactivation
Particular circumstances have sometimes “justified” the temporary disactivation of AIS. A notable example dates back to March 2026, when Greek shipowner George Prokopiou (Dynacom Tankers) decided to challenge the blockade of the Strait of Hormuz, which was then largely paralyzed by Iranian threats and ongoing combat in the region. The shipowner had at least five of his tankers transit through the strait, disabling their AIS transponders during passage and effectively navigating them in the dark. This bold but commercially astute decision came as the daily nolis for VLCCs on the Gulf of Mexico-China route had already reached $400,000 by March 2, 2026. Since then, rates have reached unprecedented levels: on October 9, the time-charter equivalent reached $1.41 million, remaining at around $1.35 million according to the latest Baltic Exchange reports.
AIS Spoofing and Dark Vessels
Apart from bold endeavors, the case of so-called “dark vessels” is naturally different. These vessels systematically resort to disactivating or manipulating transmissions to conceal their activities. However, simply turning off the transponder may not be sufficient; it is often more convenient to continue transmitting false information. A recent study has examined the possibility of falsifying even the identity of AIS coastal stations. This highlights a fundamental problem: AIS data, essential for navigation safety, do not necessarily prove the actual position of a vessel. The issue has been known for some time. In 2012, research conducted on access routes to Chesapeake Bay, along the eastern coast of the United States, compared AIS data with radar observations of maritime traffic.
Conclusion
The manipulation of AIS data poses a significant threat to navigation safety and can facilitate illicit activities. As the world continues to rely heavily on this system for maritime navigation, it is essential to address these concerns and ensure that AIS data remain reliable and trustworthy.
Original Article: Navi fantasma e segnali falsi: così la “dark fleet” russa elude le sanzioni via Ais — Blueconomy (Italian) | View English Translation