The United States military has
overseen scores of secretive ship-to-ship oil transfers to keep
Gulf energy exports flowing, using aerial and water drones as
well as helicopters in an operation to guide convoys to awaiting
tankers.
The operation on the edge of the Strait of Hormuz employs a
shuttling technique long used by Iran to skirt sanctions.
Two specific locations where the oil transfers take place
were identified by 11 people familiar with the operation – one
off the coast of Fujairah in the United Arab Emirates and the
other off Oman’s port of Sohar.
It started in early May, and at least 116 ships have been
involved in the transfers, according to shipping data and
satellite imagery reviewed by Reuters.
As recently as Tuesday morning, 12 pairs of ships could be seen
side-by-side in the Gulf of Oman: eight off the coast of Sohar
in Oman and four near Fujairah, according to satellite imagery
reviewed by Reuters. Last week on June 11, when the activity
appeared to have peaked, 17 pairs of ships could be seen
carrying out simultaneous oil transfers at the two sites,
according to images from that day.
An Apache helicopter downed by Iran on June 9, sparking
retaliatory bombings by the U.S., was involved in the mission,
according to four sources, including a former U.S. official with
knowledge of the attack. Using satellite imagery, Reuters
counted six pairs of tanker ships clustered together in a small
area off the port of Sohar the day the Apache was shot down.
Reuters could not confirm what role the Apache played in the
operation. In response to Reuters questions, a U.S. defense
official said no Central Command forces are taking part in an
offshore ship-to-ship oil transfer operation. Both crew members
were rescued by a drone boat, U.S. officials said.
The extent of the ship-to-ship transfers, how they work, and
the Apache’s role in the operation have not been previously
reported. The White House referred questions to Centcom. The
Iranian government did not respond to requests for comment about
the transfer operation.
The two spots where these transfers take place, in the Gulf of
Oman near the exit of the Strait of Hormuz, are close to the
boundaries drawn by the Persian Gulf Strait Authority, a new
Iranian body established to manage the Hormuz Strait. Ships that
fail to comply with Iran’s orders are at risk of drone and
missile attack by the Islamic Revolutionary Guard Corps.
The Fujairah port itself has come under repeated Iranian fire
during the time this U.S.-led operation has been underway. This
past weekend, according to the British maritime risk management
group Vanguard, an “unknown projectile” struck a tanker off the
coast of Oman. Vanguard said in a statement that the crew was
safe and that the impact caused some leakage of the cargo, but
no environmental damage. It did not specify whether the tanker
was involved in a ship-to-ship transfer.
Iran responded to the U.S.-Israeli war by effectively closing
the Strait of Hormuz, through which roughly a fifth of global
oil consumption normally passes. That created the biggest global
energy supply disruption in history and has spurred inflation
around the world.
The ship-to-ship transfers, though risky and inefficient, appear
to be a part of the Trump administration’s efforts to help
restore normal oil flows from the Gulf. U.S. President Donald
Trump said the Strait of Hormuz would reopen Friday under a
framework peace deal with Iran announced this week, but details
remain vague. Reuters could not determine whether the announced
deal had affected the oil transfers.
A Reuters investigation published May 20 found that Iran has
established its own system for ushering ships through the
opposite side of the Strait, involving island checkpoints,
diplomatic deals and sometimes fees.
STAGGERED DEPARTURES AND WAYPOINTS
The American transfer operations are fully controlled by the
U.S. military, said eight of the sources, including a private
security contractor who has been involved in the transfers.
Tankers must sail to a meeting point before they reach the
strait, then stagger their departures so they are around 3,000
to 4,000 meters apart, according to one of the sources as well
as satellite imagery. Their transponders are off and their
lights are dimmed, according to four sources.
A series of waypoints allow the U.S. military to monitor the
progress of the designated tankers, but the Americans are
“obviously watching you all the time,” one of the sources said.
When they pass through the strait, just beyond a zone that
Iran has delineated as under its control, the tankers pull
alongside the recipient ships, many of which are Very Large
Crude Carriers, or VLCCs, to begin the oil transfers. These take
between 24 and 40 hours to complete. The empty tankers then
shuttle back through the strait and the newly loaded VLCCs sail
onward.
What makes this ship-to-ship operation possible is that
there are a few shippers willing to sail their vessels through
the strait to deliver the oil to the waiting tankers, despite
the Iranian blockade.
But the operation is risky. “You just don’t know when Iran
might just decide to start using drones or even gunboats in
order to prevent even those ships from transiting the strait,”
said Noam Raydan, a senior fellow at Washington Institute who
specializes in maritime risk and who reviewed Reuters’ findings.
The ship-to-ship technique has been used by Iran for years
to bypass sanctions, because it masks the source of the oil. The
Iranians usually operate one pair of ships at a time, both to
avoid detection and because its prewar exports were relatively
small. The U.S.-led operation, which involves mass transfers,
gives Gulf producers better protection from Iranian retaliatory
attacks so they can move crude, condensate and petroleum
products to international buyers.
Reuters reviewed more than a dozen satellite images taken
between May 2 and June 11 showing ship-to-ship transfers
involving state-owned Gulf tanker fleets and internationally
operated vessels that receive the oil. LSEG and Kpler shipping
data reviewed by Reuters showed repeated rendezvous between
tankers operating in the area during the same period.
Based on the imagery through June 11, Reuters calculated
that at least 90 million barrels of crude oil and petroleum
products may have moved through the offshore network since early
May.
The volumes, based on the tankers’ carrying capacities, are
still small compared to the pre-war average of about 20 million
barrels that passed through the strait daily.
“As the old rules weaken, it’s ironic that the United States
is now taking a page out of the playbook of China, Russia, North
Korea, and even Iran, whose so-called ‘dark fleets’ pioneered
these techniques precisely to evade U.S. and UN sanctions,”
Michael Froman, president of the Council on Foreign Relations,
wrote in a note Friday. He was referring to the practice of
sending ships through the strait without transponders, which
Trump mentioned in comments June 10 after the downing of the
Apache.
Six sources with direct knowledge of the operation said the
U.S. has supported participating vessels through a combination
of aerial surveillance, compliance screening and monitoring
rather than naval escort. Reuters found no indication that U.S.
military personnel were directly involved in the transfers
themselves.
THROUGH THE STRAIT
The receiving side of the operation is dominated by
international tanker operators, according to a review of the
shipping records. One of them, Greece-based Dynacom Tankers
Management, has alluded to its efforts to find creative ways to
ship oil through the strait since the war began on February 28.
“Freedom of navigation is essential and nobody can impose
tolls or any other burden,” George Procopiou, Dynacom’s founder,
told a Capital Link shipping conference in Athens on June 1. “We
are here to serve, and Greece has the tradition of breaking
blockades since antiquity,” he said. “I don’t want to go into
more details, but I believe the hints are enough to understand
what I mean.”
Dynacom did not immediately respond to a request for comment
on the U.S. operation.
Another maritime source, however, said the new system
imposes its own risks on their industry.
“There is a paucity of reliable data,” the maritime security
source said. The transponders used to communicate ships
locations are switched off, “and companies are not reporting
through the usual reporting centres.” That risks collision
between the ships, which travel at night with their lights off
at speeds that don’t allow for easy maneuvering, according to
multiple shipping industry officials.
Four sources familiar with the arrangements said operators
seeking access to the system are required to undergo a
compliance review process before being allocated transit
windows. The process includes submitting information to the U.S.
Navy’s Naval Cooperation and Guidance for Shipping office in
Bahrain.
Two preliminary compliance documents reviewed by Reuters
required operators to provide complete geospatial tracking
histories, full beneficial ownership disclosure, cargo
documentation and a willingness to permit cargo testing.
If they are approved, participating vessels are then
assigned transit windows and remain in contact with the U.S.
military office in Bahrain throughout the voyage.
Emirati exports account for a substantial share of the U.S.
transfer operation, according to shipping records reviewed by
Reuters. Six of the sources said UAE’s state-owned national oil
company ADNOC has been among the most active participants in the
U.S.-led transfers.
The Kuwait Oil Tanker Company has also been active in the
transfers. Some 2.3 million barrels of crude were siphoned from
one of its ships off the coast of Sohar on June 6, one of the
busiest days for the transfers, according to TankerTrackers.com
data. The receiving ship, Sea Ruby, was spotted five days later
off India’s southwest coast and bound for China, where the cargo
was expected to be discharged.
The UAE government, ADNOC and the Kuwait Oil Tanker Company
did not respond to requests for comment.
“I don’t see a permanent solution in all of this,” said
Raydan. “This is a temporary solution amid exceptional times.”
Published on June 17, 2026
