Ship-to-Ship Oil Transfers in Gulf of Oman Plummet as Daily Hormuz Strait Transit Drops to Just Two Vessels
Miles Bennett
Iranian attacks on transiting vessels have choked the Gulf of Oman's ship-to-ship oil transfers to near-standstill, while VLCC daily transits through Hormuz have crashed from eight to two — the world's most critical crude corridor is narrowing fast.
What is happening to ship-to-ship transfers?
Ship-to-ship transfer (STS) — two tankers pulling alongside each other at sea to pump crude from one hull to another — became the backup route when direct passage through the Strait of Hormuz grew too dangerous.
Satellite imagery from July 18 shows only one tanker pair operating off Oman's coast; a week earlier, on July 11, there were three pairs. Shipping sources say just 2–3 transfers were completed in recent days.
This means → the backup channel is failing too. Both routes out of the Gulf — straight through the Strait and open-sea transfers — are narrowing at the same time.
How far has Hormuz traffic fallen?
Shipbroker Clarksons reports that over the past week, VLCC daily transits through Hormuz averaged 2, down from 5 the week before and 8 in late June to early July. Each VLCC carries up to roughly 2 million barrels.
In plain terms = in three weeks the daily count of the world's largest tankers passing through the Strait dropped from 8 to 2 — a 75% cut in capacity.
This reflects the tangible impact of IRGC attacks on transiting ships — some carriers have already begun avoiding the U.S.-escorted transit route over safety concerns.
Why does the U.S. energy secretary say public data is "inaccurate"?
Satellite signal blackouts and limited public ship-tracking data make it hard to gauge total Gulf crude exports. U.S. Energy Secretary Chris Wright called publicly available tracking data "inaccurate."
Wright's internal figures: roughly 7 million barrels per day are flowing through the Strait, with another 7 million bpd moving via bypass pipelines — a combined ~14 million bpd, about two-thirds of pre-conflict volumes and well above the March trough.
This means → Washington believes actual flows are higher than the market sees, but even on official numbers the Gulf is still running at only two-thirds of normal — the gap remains significant.
What is the key variable from here?
Since early May, the U.S.-assisted STS transfer program has moved tens of millions of barrels, partly cushioning the price impact of what is the largest oil-and-gas supply disruption on record.
Yet on Monday the IRGC claimed two tankers attempting the "unsafe southern route" had "exploded" and lost propulsion.
Put simply = whether STS operations can resume under attack pressure will determine if Gulf crude exports hold up. Wright has pledged Washington will keep the Strait open "without relying on Iranian cooperation" — but for now, the pressure is intensifying, not easing.
Content is for reference only, not financial advice.