Iran War Shipping Update - May 18, 2026

Since the outbreak of the Iran War on February 28, Iran’s “Ghost Fleet” has continued operating across key maritime routes, including loading cargoes, transiting the Strait of Hormuz, and sailing east toward China. While UANI tracking indicates that illicit shipping activity remains ongoing, the U.S. blockade initiated on April 13 is now constraining Iran’s export capacity. The blockade targets vessels entering and exiting Iranian ports, as well as ships transporting sanctioned or contraband oil, but does not apply to all Iran-linked maritime traffic. U.S. enforcement efforts have focused primarily on VLCC tankers, while smaller and support vessels continue to operate.

To read UANI’s statement on FAQs and keys facts about the U.S. blockade, click here. 

To read UANI's statement on why U.S. pressure on Iran's oil exports is working, click here.

On May 18, U.S. CENTCOM posts that U.S. forces have redirected 85 commercial ships and disabled 4 to prevent ships from entering or leaving Iranian ports since the commencement of the blockade. 

U.S. CENTCOM update on the U.S. blockade on May 18 (Credit: U.S. CENTCOM/X)

Status of the Strait of Hormuz

The Strait of Hormuz remains a critical flashpoint in the Iran War. Since the start of the conflict, 42 confirmed maritime incidents involving commercial vessels and offshore infrastructure have been reported across the Persian Gulf, Strait of Hormuz, and Gulf of Oman. 

The escalating risk has created severe congestion and instability across the Persian Gulf’s shipping lanes. Prior to the outbreak of hostilities, about 138 vessels transited the Strait of Hormuz daily. Since March 1, 2026, marine traffic data shows growing clusters of loitering vessels on both sides of the Strait of Hormuz, with many refraining from transiting due to safety concerns.

Iranian Oil-Laden Tankers Inside the U.S. Blockade

UANI has identified at least 63 tankers laden with Iranian oil — primarily crude — currently operating inside the U.S. blockade line which can be drawn from the Iranian-Pakistan border to the most eastern point of Oman. 

Map of Iranian oil laden tankers inside the U.S. blockade on May 18

Iran-linked Vessels at Chabahar Port, Iran

Iran-linked tankers are loitering and anchoring outside of the Persian Gulf at Chabahar Port, Iran. On May 16, 11 Iran-flagged tankers, as well as three Ghost Armada vessels, all laden with Iranian oil, were observed in satellite imagery near Chabahar Port. Numerous Iran-flagged and Iranian oil-laden tankers that have attempted to cross the blockade departed from Chabahar Port, with at least eight of these returning to port in response to a variety of U.S. enforcement actions. On the satellite image below, white squares denote Iran‑flagged tankers; white circles denote stateless Ghost Armada vessels.

Tankers laden with Iranian oil near Chabahar on May 16 (Credit: ESA Copernicus)

Number of Iranian Loadings

Since the outbreak of the conflict, UANI has tracked at least 73 Iranian oil loadings, 41 of which originated from Kharg Island, Iran. These shipments represent approximately 83 million barrels of Iranian oil, generating an estimated revenue of over $6 billion for the IRGC, which continues to fund Iran’s active missile and drone programs central to the conflict. This figure is notably higher than usual given the sharp increase in oil prices, including Iranian crude.

For the first time in 10 days, a tanker loaded Iranian hydrocarbons from Kharg Island on May 16, likely on account of the large oil slick first observed on May 6, and possibly as a result of pressure from the U.S. blockade.

One tanker loading at Kharg Island on May 16 (Credit: ESA Copernicus)

Iran-flagged Tankers Globally

UANI has also monitored Iran-flagged tankers operating beyond the Persian Gulf. Since the conflict began, at least 32 Iran-flagged tankers have reached Southeast Asian waters bound for the Eastern Outer Port Limits (EOPL) anchorage off Johor, Malaysia. 

On May 13, Iran flagged tanker HUGE (IMO 9357183), laden with Iranian crude, appears to be transiting the South China Sea northbound according to satellite imagery. This tanker likely departed Iran, laden with oil bound for China, after the imposition of the U.S. blockade, and likely took an uneconomical route via the Lombok Strait in Indonesia on May 3 with its AIS signal on. The tanker had previously loaded at Kharg Island on March 31, and departed from Chabahar on April 14, and was spotted near Galle, Sri Lanka on April 23. This marks a significant new operational pattern. Rather than transiting the Malacca and Singapore Straits, these tankers departed Iran, laden with oil bound for China, and likely took an uneconomical route through the Indian Ocean and the Lombok Strait in order to avoid interdiction by U.S. naval forces. HUGE now appears to be heading to a known STS location south of Hong Kong; while that spot has been used for transfers of Iranian crude before, Iran‑flagged tankers in this location represents another new operational pattern.

Iranian flagged tanker transiting the South China Sea on May 13 (Credit: Marine Traffic & ESA Copernicus)

Another Iran flagged tanker TOUR 2 (IMO 9364112), also known as KARIZ, departed the anchorage south of Hong Kong on May 18, still reporting laden. The tanker had previously departed the EOPL, despite being anchored there for over two weeks, reporting laden and broadcasting its AIS, and transited the South China Sea northbound on May 11. This is an unusual pattern of movement for an Iran flagged OFAC-sanctioned tanker.
 

Iran flagged tanker departing the EOPL on May 18 (Credit: Marine Traffic)

Meanwhile, at least 35 Iran-flagged tankers have begun returning and reporting empty to Iran from the Malaysian EOPL anchorage and Southeast Asian sea lanes, since the start of the conflict.

Iran-flagged DERYA (IMO 9569700) departed the EOPL anchorage and transited the Singapore and Malacca Straits, reporting empty with a destination of Colombo, Sri Lanka on May 18. DERYA had previously been the feeder in an STS transfer of Iranian crude in the EOPL on May 14. Like HUGE, DERYA also took the uneconomical route through the Indian Ocean and the Lombok Strait in order to avoid interdiction by U.S. naval forces. DERYA had previously appeared in the Gulf of Kutch, attempting to deliver Iranian oil at Sikka, India but departed on April 19.

DERYA transited Southeast Asian sea lanes on May 18 (Credit: ESA Copernicus)

Iran-Oil Laden Tankers off the Malaysian Coast

From February 28, the start of the conflict, to today, UANI has recorded 43 STS transfers of Iranian oil in the EOPL anchorage, a ghost fleet hotspot approximately 70 km off Malaysia’s coast. All of these transshipments have been spotted in satellite imagery.

On May 18, 37 tankers listed on UANI's Ghost Armada were anchored or loitering near the EOPL area with their AIS signals active, demonstrating that ghost fleet tankers continue to operate with impunity across Southeast Asia's sea lanes. 

Iran-Flagged Cargo Ships Globally

Despite ongoing pressure of US OFAC sanctions, approximately 30 Iranian-flagged vessels continue to operate openly across sea lanes, ports, and anchorages throughout the Indo-Pacific region. Enhanced pressure from the enforcement of the US blockade on Iran and disrupted access to Iranian ports appears to be affecting vessel schedules and operations on a large scale. This has contributed to increased instances of ships pausing and waiting in clusters at anchorages across the region.

Iran flagged cargo vessels across the Indo-Pacific on May 18 (Credit: Marine Traffic)

The Iran flagged, OFAC sanctioned container ship VELON 1 (IMO 9122473) is sailing the Arabian Sea eastbound on May 18 after crossing the Bab al-Mandab Strait on May 14 and then exiting the Gulf of Aden. The vessel departed Novorossiysk, Russia on April 23, after unknown cargo operations, and transited the Suez Canel on May 9. VELON 1 is currently reporting on AIS that it is laden and that it will arrive at Port Klang, Malaysia on May 29.

Iran flagged container ship drifting in the Gulf of Aden on May 18 
(Credit: Marine Traffic)

On May 18, there were no changes to the multiple Iranian flagged tankers and cargo vessels that continued to anchor offshore of Karachi, Pakistan. ARIES (IMO 9369722), MAHNAM (IMO 9213387), DELRUBA (IMO 9305207), WARTA (IMO 9465849),and PARNIA (IMO 9167265) were openly broadcasting on AIS while anchored about 70km offshore. The tankers STREAM (IMO 9569633), HERBY (IMO 9362059) and SOBAR (IMO 9221970) are also anchored nearby, outside territorial waters. Finally, the container ship TOUSKA (IMO 9328900) was anchored just 16 km outside Karachi port, inside Pakistani territorial waters. All of these Iran flagged vessels are OFAC sanctioned. 

Iran flagged cargo vessels near Karachi, Pakistan on May 18 (Credit: Marine Traffic and ESA Copernicus)                                                                                                                           

On May 18, the Iran flagged container ship ARTABAZ (IMO 9283007), was still drifting in the Arabian Sea approximately 170 km offshore of the Indian Coast, in the Indian Exclusive Economic Zone (EEZ). ARTABAZ departed Mumbai on April 19, after unknown cargo operations. It is possible that the ARTABAZ is loitering in this area conducting maritime surveillance in a picket pattern, as this is a highly unusual behavior for a container ship transporting routine cargo. 

Iran flagged container ship drifting in Arabian Sea on May 18 (Credit: Marine Traffic)

The OFAC sanctioned, Iran flagged container ship ARTENOS (IMO 9283021) continued to loiter at anchor in the Gulf of Kutch, outside Kandla, India. The vessel has been anchored for over three weeks since it conducted unknown cargo operations in Kandla Terminal from April 18-19. 

Iran flagged container ship anchored in Gulf of Kutch on May 18 (Credit: Marine Traffic)

The Iran flagged general cargo ship AREZOO (IMO 9165786) and containership RADIN (IMO 9820257) continued to remain anchored off Port Klang, Malaysia, inside Malaysian territorial waters; both vessels are OFAC sanctioned. The Iran flagged tanker DERYA passed the ships on its northbound transit. AREZOO conducted unknown cargo operations in Port Klang on April 17-18, and in Penang on April 15-16. RADIN arrived at the anchorage on May 5, after conducting unknown cargo ops in Zhuhai, China, on April 24-25. Zhuhai Port in China has been identified in media reports as a source of precursor chemicals for rocket fuel. The container ship TOUSKA (IMO 9328900) had also visited both Zhuhai and Port Klang, before being interdicted and seized by US forces in the Gulf of Oman on April 19.

Iran flagged container ships near Malaysia on May 18 (Credit: Marine Traffic & ESA Copernicus)

On May 18, the OFAC-sanctioned Iran flagged bulk cargo ship KIAZAND (IMO 9465758) arrived in an anchorage off Phuket, Thailand. The vessel departed Songkhla, Thailand on May 14 and passed the Singapore Strait on May 16.  KIAZAND conducted unknown cargo operations from May 3-8, in port Songkhla, before anchoring offshore Songkhla from May 8-14 and is now reporting that it is in ballast condition. It is not known what operations it may conduct in Phuket.

Iran flagged cargo ship in Gulf of Thailand on May 18 (Credit: Marine Traffic)

Six Iran-flagged cargo ships were anchored in the Malaysian EOPL anchorage area, openly broadcasting on AIS on May 18. The bulk cargo ships ARVIN (IMO 9193202), MIAMI PRIDE (IMO 9274941), BASKAR (IMO 9405942) and ANDIA (IMO 9193197) plus the container ship AZARGOUN (IMO 9283019) were joined by bulk cargo ship OURA (IMO 9387815) on May 16. OURA departed Dafeng, China, on May 7, and is currently reporting ballast status. ARVIN, reporting laden status, departed Dafeng, China on April 26. MIAMI PRIDE departed Kuantan Port on May 4. BASKAR departed Yangjiang, China on April 30, and ANDIA departed Shanghai on May 1. AZARGOUN departed Port Klang on May 11. These vessels are likely waiting in the EOPL due to the US Blockade.

Iran flagged cargo ships at Malaysian EOPL on May 18 (Credit: Marine Traffic and ESA Copernicus)

The Iran-flagged container ship BEHTA (IMO 9349590) departed Zhuhai terminal on Gaolan Island, on May 17, after one day of unknown cargo operations, and is now heading to Chang Jiang Kou (CJK) anchorage off Shanghai, according to AIS, with an estimated arrival time of May 21. The Iran-flagged container ship BEHNAVAZ (IMO 9346548) has been anchored near CJK since May 3, after also arriving from Zhuhai. The two Iran-flagged container ships SHABDIS (IMO 9349588) and SHABGOUN (IMO 9346524) remain anchored in the vicinity of Zhuhai.  All of these ships are OFAC sanctioned. SHABGOUN also completed unknown cargo operations at Zhuhai terminal on May 11 and returned to the anchorage on May 12. Additionally, BEHTA passed the vicinity of the Iranian flagged tanker, TOUR 2, also known as KARIZ.

Iran flagged container ships at Zhuhai, China, on May 18 (Credit: Marine Traffic and ESA Copernicus)