AIS Ship Tracking in the Strait of Hormuz: Inside the Crisis Shutting Down Global Oil
- Team WAKE
- 4 days ago
- 8 min read
This morning, the scenario that maritime insurers, energy traders, and naval planners have war-gamed for years became reality.
The United States and Israel launched coordinated strikes on Iran under Operation Epic Fury, targeting nuclear facilities, missile infrastructure, and military command centres across the country. Iran hit back with missiles and drones aimed at Israel, Bahrain, Kuwait, Qatar, and the UAE, where a drone struck a hotel in Dubai. Dubai International Airport, the world's busiest international hub, has halted flights indefinitely. Airspace across the Middle East is closed.
And the Strait of Hormuz, the narrow channel through which a fifth of the world's oil passes every single day, is as of this writing effectively shut.
Iranian state media are reporting the waterway is "practically closed." Ships in the area have received VHF radio broadcasts purporting to come from the Iranian Navy ordering them to hold position and avoid transit. At least eleven LNG tankers have changed navigation behaviour, slowing, turning back, or anchoring near the strait. Multiple oil majors and trading houses confirmed to Reuters they have suspended crude oil and fuel shipments through the corridor entirely. Benchmark VLCC freight rates from the Middle East to China had already tripled since the start of the year. When oil markets open Monday morning, the price signal will be severe.
We are watching, in real time, the most consequential maritime disruption since the Tanker War of the 1980s. And the intelligence tool at the centre of every decision being made right now, by insurers, traders, compliance teams, and naval commanders alike, is AIS data.
What Is Strait of Hormuz AIS Tracking and Why It Is the First Signal Anyone Reaches For
Automatic Identification System transponders are mandated by the International Maritime Organization for all commercial vessels over 300 gross tons operating internationally. Ships broadcast their identity, position, speed, course, and destination at intervals of two to ten seconds while underway, creating a near-real-time picture of vessel movements visible to shore stations and satellites around the world.
In normal times, the Strait of Hormuz AIS picture looks like a dense, orderly procession. VLCCs, Suezmax tankers, LNG carriers, product tankers, and container vessels move through the two traffic separation scheme lanes in predictable rhythm. Analysts use that baseline to spot deviations quickly.
Today, the picture looks nothing like normal. Vessels are anchoring outside expected zones, reversing course mid-transit, or disappearing from the feed altogether. Each of those signals carries immediate commercial and intelligence value, and the quality, coverage, and integrity of the underlying AIS network determines who can read them first and who is working blind.
The Insurance Market Was Already in Crisis Before This Morning
The events of today did not come from nowhere. The maritime insurance market had been flashing red for months.
Following earlier US airstrikes on Iranian nuclear facilities in June 2025, war risk premiums for vessels transiting the strait surged 60% overnight. By the time this morning's operation began, rates had already climbed from around 0.125% to between 0.2% and 0.4% of a vessel's insured value per transit. For a VLCC, that translates to an additional $200,000 to $360,000 in insurance costs for a single voyage. For vessels with any Israeli affiliation, some underwriters were quoting as high as 0.7%.
The Lloyd's Market Association Joint War Committee, which has listed the strait as a high-risk breach zone since 2018, had begun issuing seven-day cancellation notices on existing war policies, pulling coverage rather than attempting to price the risk. Some underwriters warned they might withdraw war cover from the region entirely, drawing comparisons to what happened in the Black Sea after Russia invaded Ukraine.
That threat is now a live question. With Iran retaliating against US military bases in Bahrain and Qatar, home to the US Navy's 5th Fleet and Al Udeid Air Base respectively, and Iranian naval forces broadcasting warnings to commercial shipping, underwriters face the prospect of pricing exposure they cannot observe clearly.
That observation problem is where AIS data quality stops being an analytical preference and starts being the difference between an informed decision and an expensive mistake.
BIMCO's chief safety advisor said plainly this morning: "The US-Israeli attack on Iran dramatically increases the security risk to ships operating in the Arabian Gulf and adjacent waters." The UK Maritime Trade Operations authority issued an advisory warning mariners of elevated electronic interference, including specifically disruption to AIS and other navigational systems.
That warning matters. In a conflict environment, AIS is not a passive tracking tool. It becomes an active intelligence battleground.
The AIS Battleground in the Strait
Vessels Going Dark at Scale
Turning off an AIS transponder in the Strait of Hormuz is not new. It has long been used by vessels involved in Iranian sanctions evasion, illicit ship-to-ship crude transfers in the Gulf of Oman, and other activities operators prefer not to advertise.
Today the behaviour has a different character entirely. Vessels are going dark not to evade sanctions but out of genuine fear of being targeted. Greek maritime authorities advised all Greek-flagged vessels this morning to avoid the Arabian Gulf, the Gulf of Oman, and the strait entirely. Shipping agencies in Dubai are urging crews to wait for clarity before resuming any transit.
The result is a rapidly fragmenting AIS picture. Some vessels are dark because they are hiding from Iranian naval forces. Others have switched off transponders to avoid becoming visible targets in an active combat zone. Still others may be experiencing the GPS spoofing and AIS interference that, during last June's 12-day conflict, affected an average of 1,000 vessels per day near Iranian waters, in some cases causing navigational errors and collisions.
Distinguishing between those categories, dark for evasion, dark for safety, dark due to electronic warfare, is exactly the analysis that maritime intelligence firms and insurers are trying to do in the next 72 hours. It requires dense, redundant, independently sourced AIS coverage. Where coverage has gaps, the intelligence picture has holes.
GPS Spoofing and Electronic Warfare
UKMTO's warning about AIS disruption is not hypothetical. During last June's strikes on Iran, a thousand vessels a day experienced GPS interference near Iranian waters.
Today's operation is significantly larger in scale and stated ambition than anything last summer. Electronic warfare interference in and around the strait should be treated as a baseline condition, not a tail risk.
For anyone relying on AIS data, this creates a verification problem. Signals received from vessels near the strait may include spoofed positions, false vessel identities, or corrupted transmissions. Knowing which signals to trust and which to flag as potentially manipulated depends entirely on the architecture and provenance verification capability of the network providing the data.
The LNG Picture
Among the most immediately consequential AIS signals today are the eleven or more LNG carriers that have altered their navigation behaviour near the strait. These vessels carry liquefied natural gas bound primarily for European and Asian markets that depend on the fuel for power generation and heating. Even a short supply interruption drives immediate price volatility.
Tracking these vessels in near real time, whether they are anchoring in place, turning back toward Gulf loading terminals, or making for alternative routes around the Cape, is exactly the actionable intelligence that trading desks and energy security analysts need right now. The accuracy of that picture depends on AIS receiver coverage across the Gulf of Oman and the approaches to the strait, where terrestrial stations are sparse and satellite AIS is the primary feed.
What This Means for the People Making Decisions Right Now
For maritime insurers and P&I clubs, the next 48 to 72 hours are a claims and underwriting emergency. Vessels already inside the Gulf face the prospect of being stranded, unable to exit through the strait. Some policies include specific blocking and trapping cover for this scenario. Many do not. The ability to reconstruct a vessel's exact position history, when it entered the Gulf, where it was when the strikes began, whether it received the Iranian naval warning before or after its last AIS transmission, will determine how hundreds of millions of dollars in claims are assessed. Provenance-verified AIS data in that context is not an analytical nicety. It is legal and financial evidence.
For commodity traders and energy analysts, the AIS picture in the strait is one of the only real-time signals available on the scale of supply disruption. Freight rate movements and price signals lag vessel behaviour by hours. Benchmark rates for VLCCs from the Middle East to China have more than tripled since January. The Monday open will reflect whatever the AIS picture looks like by Sunday night. Traders who can read that picture more accurately and more quickly have a genuine edge.
For compliance and sanctions teams, the crisis creates a fresh wave of exposure. Iran significantly increased its oil exports in the weeks before the strike, tripling output and pre-positioning crude on tankers near Kharg Island, the terminal through which 90% of Iranian exports normally flow. That pre-positioned oil is now somewhere in the system, on vessels that may or may not be accurately broadcasting their identity and position. The compliance challenge of separating legitimate cargoes from sanctioned Iranian crude was already difficult. Today it becomes acute.
For naval and government intelligence users, commercial AIS data provides unclassified maritime picture-building capability that can be shared across agencies and with allied nations without classification constraints. In the early hours of a rapidly evolving situation, that common operating picture has real operational value.
Why the Network Architecture Matters Now More Than Ever
Not all AIS data is equal. In a crisis, the differences between networks become decisive.
Traditional AIS data has been dominated by a small number of large aggregators running proprietary networks built over many years. The Hormuz region is among the most coverage-constrained in the world for terrestrial receivers. Geopolitical access limitations mean fixed shore stations are sparse relative to traffic volume. Signal congestion in the two TSS lanes, where hundreds of vessels transmit simultaneously on the same VHF frequencies, causes receivers to miss transmissions and log corrupted data precisely where accurate coverage matters most.
Worldwide AIS Network addresses these gaps through a fundamentally different architecture.
WWAN's decentralised receiver network distributes independently operated stations across a wider geography, providing redundant coverage in areas where proprietary legacy networks have single points of failure. In the congested approaches to the Strait of Hormuz, additional receivers mean more complete signal capture. In a crisis where vessels are altering their behaviour rapidly and unpredictably, coverage gaps translate directly into intelligence gaps.
More critically, every AIS transmission captured by the WWAN network carries blockchain-verified provenance: a cryptographically auditable record of which receiver captured it, when, and under what conditions. In an environment where GPS spoofing and AIS manipulation are active, as UKMTO has specifically warned is the case today, the ability to verify that a signal came from a specific, independently operated, geographically known receiver is the difference between trustworthy intelligence and noise.
For an insurance claims team reconstructing a vessel's position history in the strait, or a compliance team determining whether a cargo passed through a sanctioned transfer point, provenance-verified data is not just more accurate. It is defensible in a legal proceeding in a way that unverified aggregated data is not.
WWAN also offers something increasingly important in a market that has undergone significant consolidation. As major players have absorbed independent AIS networks through acquisition, the maritime intelligence data market has concentrated around a small number of infrastructure providers. Operators relying on a single consolidated source for Hormuz coverage have a fragility problem that becomes visible precisely in moments like this one.
What Comes Next
The situation is still developing rapidly. Iran has not made a formal government announcement about the strait's status. The closure signals received by vessels today came via VHF naval broadcasts rather than an official statement from Tehran. The US Navy is expected to move to secure shipping lanes, though even short-lived disruption or mine-laying operations could have severe market effects before those lanes are re-established.
It is worth noting that the Strait of Hormuz has never been fully blocked for an extended period. Iran's ability to sustain a prolonged closure against US naval opposition is limited. But the risk of targeted vessel attacks, temporary disruption, and the ongoing electronic warfare environment in and around the strait will persist for as long as the conflict continues. And its duration, by Trump's own statement this morning, is open-ended.
The maritime world is watching the AIS picture right now. Every vessel that goes dark, every tanker that turns back from the strait, every LNG carrier that drops anchor in the Gulf of Oman rather than transit toward its destination is a data point that moves markets and informs decisions worth billions of dollars.
The quality of those data points depends on who is watching, and how their network is built.
Worldwide AIS Network (WWAN) operates a decentralised, blockchain-verified AIS data network providing maritime intelligence firms, insurers, commodity traders, government agencies, and compliance professionals with high-integrity vessel tracking data. To discuss your data requirements or request a pilot, visit worldwide ais.org
All events referenced in this article reflect reporting as of February 28, 2026.