Off the coast of Venezuela, U.S. forces seized the tanker Skipper in a helicopter-launched raid, an operation confirmed by U.S. officials on 11 December, after the vessel spent weeks spoofing its GNSS-derived AIS position. The incident throws a glaring spotlight on the global ‘dark fleet’, a network of sanctions-evading tankers whose illicit movements resonate far beyond the Caribbean.
Reporting from BBC Verify (Joshua Cheetham, Paul Brown, Richard Irvine-Brown & Matt Murphy) demonstrates how the Skipper, long sanctioned under its former identity Adisa, systematically falsified its UN-mandated Automatic Identification System (AIS) broadcasts while shuttling crude oil between Iran, Venezuela, and China.
AIS is intended to provide continuous vessel location and identity data. Yet, as analysts at Kpler told the BBC, the Skipper repeatedly transmitted positions placing it at Iraq’s Basrah Oil Terminal even as terminal logs showed no trace of the ship. Satellite imagery and independent confirmation from TankerTrackers.com later placed the vessel at Iran’s Kharg Island during the same period.
The Skipper‘s disappearance from public tracking feeds between 7 November and 10 December, during which imagery confirmed its presence at Venezuela’s Port of Jose, further illustrates how spoofed or suppressed GNSS data facilitates covert loading operations. By 16 November, Kpler estimated the tanker had taken on at least 1.1 million barrels of Merey crude, later conducting additional ship-to-ship transfers off Barcelona, Venezuela.
Belgian naval analyst Frederik Van Lokeren told BBC Verify that such transfers, while not explicitly illegal, remain “extremely uncommon” for legitimate tankers, and usually indicate an effort to evade sanctions.
Timely input
It is apt to include a European voice here; over the past two years, the continent has faced persistent GNSS jamming and spoofing incidents from the Baltic to the Eastern Mediterranean, affecting commercial aviation and maritime operations.
The European Union Aviation Safety Agency (EASA) and several national regulators have warned that state-sponsored interference has grown more frequent and more tactical, highlighting vulnerabilities that mirror those exploited by the Skipper in contested maritime zones.
In this context, the Skipper seizure is not an isolated incident but part of a broader signal-integrity crisis. Whether in European airspace or in Venezuela’s offshore loading corridors, authorities now face adversaries capable of manipulating GNSS-dependent systems with impunity.
For the maritime sector, where AIS spoofing has become a hallmark of opaque, sanctions-busting operations, the episode underscores the urgent need for resilient positioning, authentication, and cross-sensor verification. Without such measures, the dark fleet will continue to navigate invisibly, even as its shadows extend across continents.
