Hormuz Undersea Cables Watched as Iran-Linked Ships Go Dark

Four Iran-linked vessels spent October slowing, looping and switching off their trackers directly above the Hormuz undersea cables that carry much of the Gulf's internet traffic. Maritime analytics firm Windward flagged the pattern in an October 29 report, and the Financial Times brought it to wider attention on November 6. No cable has been cut, but the timing lines up with a string of explicit Iranian threats against the region's digital infrastructure.

What did the ships actually do over the cables?

Three of the vessels are tankers under US sanctions and the fourth is a small Iranian fishing boat with no known owner. According to Windward, they sailed normally until they reached a specific cable corridor, and only then slowed, looped, turned back, loitered or went dark. The firm said that behavior fits the profile of mapping cable routes, or placing charges or mines while the ships' AIS transponders were off.

The most detailed case is Celestial Sea, an Iran-flagged products tanker that US Marines boarded in the Gulf of Oman in May. On October 14 it drifted in a loop for more than four hours beside the 2Africa cable. The next day it went dark inside the 2Africa and Bay of Bengal Gateway corridors off Sohar, stayed invisible for 86 hours, then reappeared nine nautical miles away and made a U-turn over the second cable. It carried no cargo the whole time.

A gas carrier loaded with roughly half a million barrels of Iranian LPG left the same anchorage for Malaysia on October 23. Ten hours out it slowed over 2Africa, turned 180 degrees back toward Oman and switched off its transponder. A crude tanker run by Iran's state tanker company crawled at under one knot for about ten days between Jask and Chabahar, within a few miles of four cable routes. The fishing boat sat over the Europe India Gateway and Transworld cables from October 21 to 26.

Why does the timing matter?

The movements followed a run of warnings from Tehran. On October 12, Mohsen Rezaei of the Supreme National Security Council said data centers and AI facilities would be destroyed if the war resumes. On October 19, Revolutionary Guards spokesman Hossein Mohebbi pointed out that seven cables run under the strait and promised new targets and new weapons. Two days later, the Guards' political deputy Yadollah Javani said the cables would be hit in retaliation for any attack on Iranian infrastructure.

How much traffic runs through the Hormuz undersea cables?

Counts differ slightly by source. TeleGeography data cited in the coverage puts six active cables through the strait, with Fibre in Gulf, SEA-ME-WE 6 and 2Africa still being built. Their owners include Meta, Vodafone, Orange, AT&T, Verizon, BT and China Mobile.

Country or market	Exposure to the Hormuz cables
Iraq, Kuwait, Bahrain, Qatar	International connectivity depends entirely on cables under the strait
India	About a third of westbound internet traffic passes through the Gulf route
Europe, Africa, Asia	Linked to the Gulf by the same corridors, so cuts would force rerouting

A cut would not just slow down browsing. Cloud regions and data centers in the Gulf rely on these links to reach users and sync with the rest of the world, and repair ships need safe access to work on a damaged segment.

Could satellites fill the gap?

Only partly. Satellite services such as Starlink can keep critical links alive, but they carry a tiny fraction of what a modern fiber pair moves. Operators would mostly lean on overland routes and spare capacity on cables that avoid the strait.

Our Take

Ship tracks are evidence of intent only up to a point, and Windward itself says where the three still-dark vessels resurface will show whether the cables were the destination or just a stop. Still, empty tankers drifting for days over the exact corridors Tehran named is the kind of signal cable owners cannot ignore. For readers in Türkiye, the story is a reminder that much of the region's traffic leans on a handful of chokepoints, and the Red Sea cable cuts of 2024 showed how slowly those get fixed.