**More than Half of Hormuz Tanker Routes Remain a Mystery**
The Strait of Hormuz, a critical passage for global oil and gas shipments, is facing a significant challenge as nearly two-thirds of tanker crossings since mid-July have occurred without active tracking signals. This lack of visibility is causing concern among oil traders, shipowners, and regulators, who are left with an incomplete understanding of this vital energy route.
Data from Signal Group indicates that approximately 62 percent of the 102 recorded tanker transits through the strait since July 14 were conducted with the Automatic Identification System (AIS) turned off. This practice is especially prevalent among crude oil carriers, with 79 percent of such transits—33 out of 42—occurring without an active signal. In contrast, 50 percent of clean petroleum and product tanker crossings, or 30 out of 60, were also AIS-dark.
The implications of this trend extend beyond mere tracking; they pose direct challenges to the shipping sector in Cyprus. The absence of reliable tracking complicates route planning, chartering decisions, sanctions checks, and insurance assessments. As each voyage through the Strait of Hormuz carries increased financial and operational risks, the shipping industry is grappling with the consequences of this information gap.
Adding to the complexity, the ownership profiles of the vessels involved further obscure the situation. Signal Group reports that 56 percent of all tanker transits are linked to non-transparent interests. This includes 29 vessels associated with sanctioned fleets, 17 linked to opaque ownership structures, and 11 attributed to what is known as the "ghost fleet." Only 44 percent of the transits were under the control of named and transparent owners.
Traffic through the strait has continued in both directions, with 55 vessels moving from east to west and 47 traveling in the opposite direction. However, determining the specific lanes used has proven challenging. Only four transits were confirmed through the Omani lane, while 45 were identified along the Iranian side of the strait. For the remaining 53 voyages, insufficient AIS coverage has made it impossible to reliably establish their routes.
The lack of tracking signals does not inherently indicate illegal activity. According to guidelines from the International Maritime Organization (IMO), shipmasters may deactivate AIS if continuing to transmit could jeopardize the vessel's safety or security, particularly in the face of imminent threats. However, past instances of AIS manipulation have been associated with attempts to conceal sanctions violations and ship-to-ship transfers. The Baltic and International Maritime Council (BIMCO) emphasizes that the absence of a signal alone is not sufficient to prove wrongdoing; the context of each blackout must be carefully considered.
Recent statistics from Lloyd’s List Intelligence reveal a troubling trend, with nearly 70 percent of observed tanker transits during the week of July 13 to 19 occurring without AIS, an increase from 55 percent the previous week and 42 percent two weeks prior. Additionally, the volume of vessels using the Strait of Hormuz has significantly decreased, with only six vessels crossing on a recent Monday, compared to a ten-day average of about 11 and a pre-conflict norm of 130 to 140 ships per day.
The implications of the information gap extend beyond the shipping industry. The U.S. Energy Information Administration estimates that 20.9 million barrels of oil per day passed through the Strait of Hormuz in the first half of 2025, accounting for about 20 percent of global petroleum consumption and one-quarter of internationally traded seaborne oil. The strait also plays a crucial role in global liquefied natural gas trade, particularly in exports from Qatar.
As commercial risks escalate, war-risk premiums for vessels navigating the region have surged, fluctuating between 3 and 10 percent of a ship's value during the ongoing conflict, compared to just 0.25 percent prior to hostilities. For a tanker valued at $100 million, this translates to potential insurance costs ranging from $3 million to $10 million for a single voyage through the strait.
Currently, the Strait of Hormuz presents two distinct traffic pictures: the vessels visible on tracking screens and those whose movements must be reconstructed post-facto. For shipping companies and energy markets striving to ascertain the volume of oil being transported, its destinations, and the entities controlling these shipments, the latter picture is becoming increasingly critical. As the situation evolves, stakeholders in the shipping and energy sectors will need to navigate these complexities to mitigate risks and maintain operational integrity.