Tankers carrying crude and refined oil through the Strait of Hormuz have increasingly been switching off their automatic identification system transponders, masking vessel identities and deploying anti-drone defences, delegates told a conference this week. The behaviour was described by panellists at APPEC 2026 on 10 September and reported on 11 September 2026.
Panel members said the practice of disabling AIS was becoming more common among vessels transiting the waterway even as oil continued to flow. Comment at APPEC indicated operators were combining identification blackouts with additional defensive measures aimed at small unmanned aircraft.
Speakers at the session gave a wide range of estimates for the volume of oil still moving through Hormuz. The panel’s figures were described as spanning a broad spectrum, underlining uncertainty about the scale of current flows through the chokepoint.
Max Tay, Repsol’s head of heavy products in Asia, was among those who spoke on the panel about changes to vessel behaviour and reporting practices in the strait. Sources carried the account of the APPEC discussion on 11 September 2026.
AIS signals and identity masking
Delegates at APPEC identified the disabling of automatic identification system transponders as a notable and growing trend for tankers transiting Hormuz. The practice masks ship identities from routine monitoring systems and was flagged alongside other operational changes.
Speakers linked the blackout of electronic identification to altered operating patterns in the waterway, though the APPEC session described a range of perspectives rather than a single consensus view.
Defensive measures and estimates of flow
Panellists also reported that some tankers were deploying anti-drone defences while continuing to transit the strait. These measures were discussed in the context of protecting vessels from the increasing proliferation of small unmanned aerial systems.
Estimates of oil flows through Hormuz given by the panel covered a broad span, reflecting divergent assessments among industry participants. The variation in figures presented at APPEC highlighted differing methodologies and levels of confidence among those offering estimates.
The APPEC forum on 10 September provided the platform for the comments; sources published a report of the discussion on 11 September 2026. The coverage relayed the panellists’ accounts without presenting a single consolidated figure for flows or an authoritative tally of vessels operating without AIS.
Industry observers at the conference described operational changes but also emphasised the range of views on how widespread the practices are and what they mean for longer‑term traffic patterns. The session’s contributions underlined that while movement of cargo persists, the means of monitoring and reporting that movement have been subject to recent adjustment.
The discussion at APPEC and the subsequent report by reports offered a snapshot of current industry concern about transparency and security in one of the world’s most watched maritime corridors. Panellists’ remarks confirmed that oil continues to transit the strait even as operators alter how they present and protect their vessels in transit.