Skip to content
You can now search across every topic, entity and event.What's new
European Oil Markets
4JUN

GPS blacked out across Gulf chokepoints

2 min read
10:20UTC

US and British maritime authorities confirm an electronic warfare corridor stretching 2,500 kilometres across two of the world's three critical sea lanes. There is no safe detour.

EconomicDeveloping
Key takeaway

An electronic warfare corridor now links two chokepoints, leaving no safe maritime alternative.

MARAD Advisory 2026-004 and UKMTO data confirm severe GNSS/GPS interference extending from the strait of Hormuz across the Gulf of Oman and into the Red Sea near Bab al-Mandeb 1. This is not a side effect of military operations but a deliberate electronic denial zone spanning two of the world's three critical maritime chokepoints.

No modern peacetime precedent exists for electronic warfare denial at this scale. During the Tanker War (1987 to 1988), mines and missile boats threatened individual vessels. The current denial threatens the navigational infrastructure itself, degrading the ability of any vessel to determine its own position across a 2,500-kilometre corridor. The Houthis threatened Bab al-Mandeb closure the day after Pakistan confirmed talks had stalled.

Vessels diverting from Hormuz toward the Red Sea now navigate degraded positioning systems approaching a second contested chokepoint. Roughly 4.5 million barrels per day and 12% of global trade pass through Bab al-Mandeb. Combined with near-total Hormuz closure, the world's two most important oil chokepoints are under simultaneous pressure for the first time since the 1973 oil crisis 2. The Cape of Good Hope route adds 10 to 14 days and $500,000 to $1 million per voyage in fuel costs.

Deep Analysis

In plain English

Ships navigate using GPS-style satellite signals. Someone is deliberately jamming those signals across a 2,500-kilometre corridor stretching from the Strait of Hormuz in the Gulf to the Bab al-Mandeb in the Red Sea. This matters because ships diverted away from Hormuz (which Iran controls) have been heading toward the Red Sea instead. The GNSS jamming makes that alternative route significantly more dangerous, because ships cannot accurately determine their own position. The practical effect: there is now no safe, insurable sea route between the Gulf and global markets. Ships must go around Africa instead, adding 10 to 14 days and significant fuel costs to every voyage.

First Reported In

Update #51 · Iran hits aluminium plants; Hormuz emptying

International Maritime Organisation / UKMTO· 29 Mar 2026
Read original
Different Perspectives
Kuwait
Kuwait
Kuwait absorbed the Iranian strike that knocked generating units offline at a combined power-and-desalination plant on 17 July, the event that finally moved freight and insurance in lockstep with Brent. The strike hit essential civilian infrastructure, not a trading desk's benchmark.
Asian buyers (Singapore)
Asian buyers (Singapore)
Singapore's middle distillates rose 12% month-to-date to 8.91m barrels and fuel oil passed 19m barrels on a 105% net-import surge, buyers retaining barrels as the East-West arbitrage window narrows. Cargoes are being stockpiled ahead of further Hormuz-driven freight repricing rather than released west.
Austria (Coreper holdout)
Austria (Coreper holdout)
Vienna is blocking the same package over roughly EUR 2bn of frozen Russian assets earmarked for Raiffeisen, a domestic banking dispute with no connection to the oil cap racing toward its 23 July expiry. The linkage forces the whole package to wait on a bilateral compensation fight.
Greece (Coreper holdout)
Greece (Coreper holdout)
Athens is holding the 21st sanctions package at the 22 July Coreper vote over Russian LNG re-export rights, a condition unrelated to the oil price cap itself, leaving the $44.10 freeze one day from expiry without a deal. Greece's own tanker registry gives it a direct stake in how any shadow-fleet measures are drafted.
Marine underwriters (Gulf war-risk)
Marine underwriters (Gulf war-risk)
Hull war-risk cover for Hormuz transits widened to a 3-10% band on 17 July with 5% the emerging norm, up from a 3-4% baseline set in late June, the first repricing in six weeks to track a flat-price move rather than lag it. Cover resets on actuarial evidence of loss, not on diplomatic or price signals.
Money managers (CFTC-tracked)
Money managers (CFTC-tracked)
The CFTC's week-to-14-July snapshot, released 17 July, showed WTI managed-money net long collapsing 69% to 19,783 contracts and a standalone 60,141-contract net short on Brent Last Day (NYMEX). Both readings predate the Kuwait strike and the 20 July escalation, so any covering since is not yet visible in public data.