Sanctioned Iran-Linked Tankers Went Dark Over Gulf of Oman Cables as the IRGC Threatened Them

At a Glance

• Between October 5 and 28, three U.S.-sanctioned tankers and an Iran-flagged fishing-support vessel slowed, looped, turned back, and went dark over the undersea cable corridors off Oman’s Batinah coast and the Iranian Makran coast.
• CELESTIAL SEA went dark inside the 2Africa and Bay of Bengal Gateway corridors for 86 hours, a second turned away from its declared destination right after slowing on 2Africa, and the third loitered for about 10 days near four cable routes in Iran’s EEZ.
• All three belong to networks that have moved oil for Iran’s state oil company or its military, and one is operated by Iran’s state tanker company.
• A 34-meter Iranian fishing-support vessel with an unknown beneficial owner drifted along the EIG and TW1 routes in waters it had never entered, then went dark and has not reappeared.
• The activity overlapped with a run of Iranian threats against Gulf cables, including an October 23 report that Tehran has detailed plans to target them if the U.S. and Israel attack Iran again.
• Cargo logistics do not explain the moves, which fit the profile of mapping cable routes or placing charges on them while dark.

Seven Cable Systems Run Through the Corridor

The waters off Oman’s Batinah coast carry one of the densest concentrations of undersea cables in the region. Seven systems pass through the corridors where the three tankers operated, namely 2Africa, Bay of Bengal Gateway (BBG), Asia Africa Europe-1 (AAE-1), the Oman Australia Cable (OAC), Europe India Gateway (EIG), Transworld (TW1), and SeaMeWe-4.

Between them, these cables connect Oman, the UAE, Saudi Arabia, Qatar, Kuwait, Bahrain, Iraq, Pakistan, India, Sri Lanka, Egypt, and Europe, with OAC running onward to Australia. Their owners include Meta, Vodafone, Orange, AT&T, Verizon, BT, China Mobile, China Telecom, Reliance Jio, Omantel, e&, and many of the region’s major telecom operators. Damage here would ripple well beyond the Gulf.

Loops, U-Turns, and Days in the Dark

A Loop and an 86-Hour Blackout Off Sohar

On October 14 and 15, CELESTIAL SEA (IMO 9397030), a U.S.-sanctioned, Iran-flagged products tanker, drifted in a loop for 4.3 hours at 0 to 1.4 knots, 0.65 nautical miles from the 2Africa corridor. On October 15, it went dark inside the 2Africa and BBG corridors off Sohar. It stayed dark for 86 hours and came back transmitting only about 9 nautical miles from where it went dark. When it reappeared on October 19, it made a U-turn above BBG and then anchored off Shinas. The tanker was in ballast throughout, according to Vortexa data.

A Laden Gas Carrier Turns Away From Malaysia

A U.S.-sanctioned very large gas carrier (VLGC) was anchored next to CELESTIAL SEA. On October 23, the VLGC left Shinas for Pasir Gudang in Malaysia, laden with about 494,500 barrels of LPG, according to Vortexa data. Ten hours later, it slowed below 3 knots for 42 minutes inside the 2Africa corridor, with OAC and BBG 2.5 to 4 nautical miles away. It then turned 180 degrees back toward Oman, away from its destination, and went dark about 2 nautical miles from AAE-1. As of October 28, it had been dark for five days.

Ten Days Loitering Between Jask and Chabahar

The third tanker, an Iran-flagged very large crude carrier (VLCC) in ballast according to Vortexa data, loitered at under 1 knot for about 10 days in Iran’s EEZ between Jask and Chabahar, 0.4 to 3 nautical miles from the EIG, TW1, BBG, and SeaMeWe-4 routes. It went dark repeatedly, including for 33 hours from October 17. On October 18, it met an Iran-flagged vessel with no IMO number. It has been dark since October 26.

Three Tankers With Direct Ties to Iran’s State and Military

All three tankers are part of Iran’s sanctioned oil trade.

CELESTIAL SEA was sanctioned by OFAC in April 2025, under its former name HARMONY, as part of the fleet of a UAE-based operator whose vessels moved oil for the National Iranian Oil Company (NIOC) and, in 2023, for the Iranian military, according to the U.S. Treasury. The operator also worked with associates of a Houthi financial official. The tanker has used an Iranian call sign and an Iranian MMSI, and it swapped identities with another tanker in August 2025. In May, U.S. Marines boarded it in the Gulf of Oman on suspicion of trying to break the U.S. blockade.

The VLCC flies Iran’s flag and is operated by the National Iranian Tanker Company (NITC), the state tanker company. Treasury sanctioned NITC in 2020, together with the Petroleum Ministry and NIOC, for funding the IRGC Quds Force. The VLCC’s registered owner is also listed by the UK and EU. The tanker has broadcast two other names and has met the same Iran-flagged vessel about nine times since August.

The VLGC was sanctioned in April 2026, together with its Panama-based owner, for carrying about two million barrels of Iranian LPG since early 2025, according to Treasury. It changed its MMSI and call sign in May and June, took on a Vietnamese operator, and was dark for 877 hours in August and September. At the Shinas anchorage, both the VLGC and CELESTIAL SEA met other vessels.

A Fishing-Support Vessel Worked the Same Cables

The pattern is not confined to the sanctioned tanker fleet.

A 34-meter Iran-flagged general cargo vessel that Windward tags as part of a fishing support fleet resumed transmitting on October 5 in the offshore Gulf of Oman southeast of Jask, in an area it had never entered in its AIS record since November 2024. After a stop about one kilometer off the Iranian Makran coast on October 8, it went dark for almost twelve days in the same area.

From October 21 to 24, it loitered at 0.1 to 0.5 knots along the EIG and TW1 routes, moving back up-current at about 3 knots and drifting again, passing over EIG on October 22 and holding 0.4 to 1.7 nautical miles from TW1 for roughly 30 hours on October 23 and 24. On October 25, it crossed FALCON and the UAE-Iran cable off Jask, then sailed north into Iranian waters. It has been dark since October 26.

Its ownership is opaque. The owner and manager operate only this vessel, and its beneficial owner has been unknown since August 2025. Windward assesses its IUU fishing risk as High.

Nothing public ties the company to the Iranian state. Two things are worth noting alongside that. Fishing in Iranian waters requires a licence from the state fisheries company Shilat, per FAO and UNEP. And the IRGC Navy has organized fishermen and their boats into a naval Basij that its commander described as a shadow navy, in which people enter the battle with their own vessels.

Iran has used civilian and commercial hulls for intelligence collection before. The IRISL-owned SAVIZ and BEHSHAD, both registered as cargo ships, served as IRGC intelligence platforms passing targeting data to the Houthis. On October 6, U.S. forces destroyed an Iranian-linked dhow in the Gulf of Oman that CENTCOM said was conducting surveillance on U.S. Navy ships, and the IRGC has turned to unarmed spotters on small boats to identify targets.

The area is a busy fishing ground. What does not fit that explanation is a small vessel with a concealed beneficial owner working slowly along two cable routes in waters it had never visited, during the weeks the IRGC was threatening those cables.

Iran Threatened the Cables in the Same Weeks

The three tankers worked the cable corridors in the same weeks Iran threatened the cables.

On October 12, two days before CELESTIAL SEA’s loop, Iran’s security chief Mohsen Rezaei warned that cables and data centers across the region could be attacked if the war resumes. On October 19, IRGC spokesman Hossein Mohebbi said seven major internet cables run under Hormuz and that this time Iran’s response would be much harsher. On October 21, Yadollah Javani, political deputy to the IRGC chief commander, warned that attacks on Iranian infrastructure could bring retaliation against the Hormuz cables, according to Tasnim.

On October 23, the day the VLGC slowed and turned back on 2Africa, two senior Iranian security officials noted that Tehran has detailed plans to target the Gulf’s undersea cables if the U.S. and Israel attack Iran again, and would try to prevent repairs to prolong the outage.

Iran already uses merchant vessels for intelligence and military operations. The IRGC used two cargo ships belonging to the state-owned Islamic Republic of Iran Shipping Lines (IRISL) off Yemen to support the Houthis, including passing them targeting data and vessel tracks. Earlier this month, two other sanctioned Iran-linked tankers drifted for days over the same corridors.

Iran-affiliated channels have also circulated an AI-generated video threatening to cut the Gulf’s cables, pushed by accounts assessed as troll operations. The provenance is unestablished, but the amplification places the threat in the information space alongside the official statements.

Houthi attacks resumed after Saudi defense minister’s visit to Iran, despite Pakistani, Turkish, and Qatari mediation efforts. And the latest was suspected Iranian troll accounts releasing this AI generated clip threatening cutting off Gulf internet cables https://t.co/JY1WqmBap3

— Ahmed Quraishi (@_AhmedQuraishi) October 29, 2026

Why Cargo Logistics Don’t Explain the Moves

Vessels waiting off Shinas sit near the cables anyway, but cargo logistics don’t explain these moves. The VLCC and CELESTIAL SEA were empty, so their days of loitering were not floating storage. The VLGC was laden with a cargo already ordered to Malaysia, and it turned back off Muscat, far from the U.S. blockade line, right after slowing on the 2Africa corridor. CELESTIAL SEA went dark over two corridors and came back transmitting 86 hours later only 9 nautical miles away, rather than waiting at the anchorage.

The fishing-support vessel carried no cargo rationale at all. It drifted at under half a knot along two cable routes in an area outside its two-year operating history, then left.

For vessels from networks that already work for Iran’s state and military, that fits the profile of mapping the cable routes, or of placing charges or mines on them while dark, ahead of the attacks Tehran says it has planned.

What to Watch

Three of four tankers remain dark, and where and when they reappear will show whether the cable corridors were the destination or a stop along the way. Further loitering by sanctioned Iran-linked tankers over the Batinah corridors, especially alongside new IRGC statements on the cables, would confirm a pattern rather than a coincidence.

Written by Maya Romi, Senior Content Manager, Windward; analysis by Gilad Karo, Maritime Analyst, MIOC.