An oil tanker seized by the US off the Venezuelan coast on Wednesday spent years trying to sail the seas unnoticed.
Changing names, switching flags, and vanishing from tracking systems.
That all came to an end this week, when American coast guard teams descending from helicopters with guns drawn stormed the ship, named Skipper.
A US official said the helicopters that took the teams to the tanker came from the aircraft carrier USS Gerald R Ford.
The sanctioned tanker
Over the past two years, Skipper has been tracked to countries under US sanctions including Iran.
TankerTrackers.com, which monitors crude oil shipments, estimates Skipper has transported nearly 13 million barrels of Iranian and Venezuelan oil since 2021.
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And in 2022, the US Treasury Office of Foreign Assets Control (OFAC) placed Skipper, then known as Adisa, on its sanctions list.
But that did not stop the ship’s activities.
In mid-November 2025, it was pictured at the Jose Oil Export Terminal in Venezuela, where it was loaded with more than one million barrels of crude oil.
It left Jose Oil Export Terminal between 4 and 5 December, according to TankerTrackers.com.
And on 6 or 7 December, Skipper did a ship-to-ship transfer with another tanker in the Caribbean, the Neptune 6.
Ship-to-ship transfers allow sanctioned vessels to obscure where oil shipments have come from.
The transfer with Neptune 6 took place while Skipper’s tracking system, known as AIS, was turned off.
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Dimitris Ampatzidis, senior risk and compliance manager at Kpler, told Sky News: “Vessels, when they are trying to hide the origin of the cargo or a port call or any operation that they are taking, they can just switch off the AIS.”
Matt Smith, head analyst US at Kpler, said they believe the ship’s destination was Cuba.
Around five days after leaving the Venezuelan port, it was seized around 70 miles off the coast.
Moving in the shadows
Skipper has tried to go unnoticed by using a method called ‘spoofing’.
This is where a ship transmits a false location to hide its real movements.
“When we’re talking about spoofing, we’re talking about when the vessel manipulates the AIS data in order to present that she’s in a specific region,” Mr Ampatzidis explained.
“So you declare false AIS data and everyone else in the region, they are not aware about your real location, they are only aware of the false location that you are transmitted.”
When it was intercepted by the US, it was sharing a different location more than 400 miles away from its actual position.
Skipper was manipulating its tracking signals to falsely place itself in Guyanese waters and fraudulently flying the flag of Guyana.
“We have really real concerns about the spoofing events,” Mr Ampatzidis told Sky News.
“It’s about the safety on the seas. As a shipping industry, we have inserted the AIS data, the AIS technology, this GPS tracking technology, more than a decade back, in order to ensure that vessels and crew on board on these vessels are safe when they’re travelling.”
Dozens of sanctioned tankers ‘operating off Venezuela’
Skipper is not the only sanctioned ship off the coast of Venezuela.
According to analysis by Windward, 30 sanctioned tankers were operating in Venezuelan ports and waters as of 11 December.
The tanker seizure is a highly unusual move from the US government and is part of the Trump administration’s increasing pressure on Venezuelan President Nicolas Maduro.
In recent months, the largest US military presence in the region in decades has built up, and a series of deadly strikes has been launched on alleged drug-smuggling boats in the Caribbean Sea and eastern Pacific Ocean.
In the past, Mr Ampatzidis explained, actions like sanctions have had a limited effect on illegally operating tankers.
But the seizure of Skipper will send a signal to other dark fleet ships.
“From today, they will know that if they are doing spoofing, if they are doing dark activities in closer regions of the US, they will be in the spotlight and they will be the key targets from the US Navy.”
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The Data X Forensics team is a multi-skilled unit dedicated to providing transparent journalism from Sky News. We gather, analyse and visualise data to tell data-driven stories. We combine traditional reporting skills with advanced analysis of satellite images, social media and other open source information. Through multimedia storytelling we aim to better explain the world while also showing how our journalism is done.
