Hormuz AIS anomalies spike

For years, the Strait of Hormuz was the closest thing oil shipping had to a six-lane highway. On April 9, Lloyd’s List reported that flows had fallen so far that more than 600 vessels were still stuck in or around the Gulf system, even after a ceasefire. (lloydslist.com) This is the narrow waterway between Iran and Oman that carries a huge share of the world’s seaborne oil and liquefied natural gas. Reuters, via gCaptain, described it last month as a chokepoint for about a fifth of global seaborne oil and liquefied natural gas trade. (gcaptain.com) The traffic jam did not happen because the sea got physically blocked by mines or sunken ships. Lloyd’s List reported that many owners stopped moving because of Iranian warnings, insurance problems, and a new Iranian approval system that turned normal commercial transit into a case-by-case negotiation. (lloydslist.com) By mid-March, Iran had shifted ships into a corridor that runs close to Larak Island inside Iranian-controlled waters. Lloyd’s List reported that vessels using that route needed pre-approval, clearance codes, and in some cases escorts linked to the Islamic Revolutionary Guard Corps. (lloydslist.com) That is why a sudden collapse in visible traffic near Larak Island gets attention. Windward wrote on April 8 that even the ships still moving were using the controlled corridor around Larak Island instead of standard commercial lanes, which means a small change in permissions can make the map look almost empty. (windward.ai) The second layer of the story is Automatic Identification System, the radio beacon ships use to broadcast identity and position. Windward warned months before this crisis that the Strait of Hormuz was already seeing more Automatic Identification System spoofing, extreme Global Positioning System jamming, and other signal problems that can make a ship’s track look wrong or disappear. (windward.ai) So when trackers started flagging 180-degree turns, analysts were not just watching captains change their minds. They were looking for the difference between a real U-turn, a ship waiting for permission, and a manipulated signal in one of the most monitored pieces of water on earth. (windward.ai) One vessel drawing attention was the Panama-flagged products tanker AUROURA, which VesselFinder lists under International Maritime Organization number 9262912. The Times of Israel, citing the ship-tracking post, said AUROURA was turned away near the strait and noted that the vessel is sanctioned by the United States Treasury for carrying Iranian oil. (vesselfinder.com) (timesofisrael.com) Another reason these reversals stand out is who is still moving. TradeWinds reported in late March that sanctioned ships were dominating the reduced tanker traffic through Hormuz, while many mainstream operators stayed out. (tradewindsnews.com) That creates a strange picture on the map: fewer ships overall, more politically exposed ships in the lane, and more incentive for some operators to go dark or hug unusual routes. Lloyd’s List reported in March that some owners were even weighing night transits with Automatic Identification System switched off. (lloydslist.com) The result is that a near-empty strait and a couple of sharp reversals are not just odd tracking screenshots. In April 2026, they are clues to a shipping system that is still moving only under selective approval, close surveillance, and constant pressure from sanctions, insurance, and signal interference. (lloydslist.com)