Limpet Mines Return to the Gulf as Iran Strikes Four Tankers Near the Strait of Hormuz

At a Glance

• Since October 29, Iran has attacked at least four tankers in and around the Strait of Hormuz.
• One attack used explosive devices fixed to a tanker’s hull by a small boat, the first use of limpet mines in the Gulf region since at least 2019.
• Three of the four tankers had been operating dark, and at least two are assessed as part of the “STS shuttle” moving Gulf cargoes through the Strait.
• Iranian sources claimed four tankers hit mines in the Strait and caught fire, though it is unclear whether that refers to vessels beyond the four confirmed.
• Transits have not slowed, with about 24 AIS-visible transits between October 30 and the morning of November 1, compared with 18 in the same window two days earlier.

Four Tankers Hit in Three Days

Between October 29 and 30, Iran attacked at least four tankers across the Strait of Hormuz and the waters around it. The attacks ranged from projectiles to hull-mounted explosives, and they struck laden and empty vessels, Qatari- and UAE-owned tonnage, and tankers that had spent weeks operating dark. Iranian sources separately claimed that four tankers hit mines in the Strait and caught fire, but it is unclear whether they were referring to additional vessels beyond the four confirmed.

Projectiles Strike a Laden LNG Carrier Inside the Gulf

On October 30, AL MAYEDA (IMO 9397298), a Marshall Islands-flagged, Qatari-owned LNG carrier, laden with an unknown quantity of LNG according to Vortexa, was struck by three projectiles around 18:00 UTC, approximately 40 nautical miles south of Lavan Island. Windward data show AL MAYEDA turning around at 18:33 UTC before going dark at 22:17 UTC.

AL MAYEDA had previously been dark between September 27 and October 30, and crossed inbound through the Strait of Hormuz during that period.

Limpet Mines Return to the Gulf

The same day, a small boat approached LOUISE 1 (IMO 9290323), a Panama-flagged, Panama-owned crude oil tanker, approximately 25 nautical miles northeast of Khasab, Oman, and emplaced two explosive devices on its hull. The explosion caused a fire in the engine room and briefly disabled the vessel.

LOUISE 1 was last reported laden with 1.02 million barrels of crude on September 28, according to Vortexa, at its last AIS-reported position 12 nautical miles east of Khor Fakkan. It has not reported a position since.

Dark Shuttle Tankers Come Under Fire

Two more tankers were hit while likely transiting the Strait dark.

RITI (IMO 9249075), a Panama-flagged, Marshall Islands-owned crude oil tanker in ballast, according to Vortexa, was attacked in the Strait on October 30, likely during a dark inbound transit, and caught fire. Oman evacuated 25 crew members from the vessel 1.6 nautical miles off the Musandam Peninsula. RITI’s last known AIS position was on October 29, approximately 36 nautical miles east of Khor Fakkan. NASA FIRMS imagery did not detect a thermal anomaly off Musandam during this period, likely indicating the fire was extinguished.

On October 29, ARZANAH (IMO 9928023), a Liberia-flagged, UAE-owned crude oil tanker, was targeted while transiting an undisclosed part of the Strait. Vortexa last reported it laden with 2.14 million barrels of crude on October 17, and it has been dark since that date.

Why the Return of Limpet Mines Matters

This latest round of attacks continues the trend established this month while expanding the methods Iran is using. Limpet mines are a cost-effective weapon against tankers. They were last successfully used in the region in 2019, when multiple tankers were targeted at anchorages in the Gulf of Oman.

The shift matters because it widens the threat beyond projectiles. A small boat that can approach a tanker and place explosives on its hull turns any slow-moving or anchored vessel into a potential target, including the dark shuttle tankers that rely on staying off AIS to avoid detection. This threat is particularly acute inside the Strait, where the ability to maneuver is already limited and small boats are regularly moving inside the waterway.

Transits Are Still Rising

The attacks, along with ongoing rhetoric about a possible resumption of combat operations in the Middle East, have not reduced Strait of Hormuz transits. Between October 30 and the morning of November 1, there were approximately 24 AIS-visible transits, compared with 18 AIS-visible transits in the same window between October 28 and 30.

Shipowners continue to show a willingness to transit the Strait despite almost daily attacks from Iran. This very likely reflects the attraction of high freight rates for operators willing to take on the risk, and the continued push by Gulf States to move oil through the STS shuttle.

Outlook

That willingness has a limit. Should combat operations resume at a level of intensity similar to the first week of March, transits, already modest, would be expected to fall to near zero within the first 72 hours of the conflict as shipowners reassess the risk of exposure in the Strait.

Analysis by Matthew Mueller, MIOC Team Leader.