Een Brits marineschip vlakbij supertanker Grace 1.
© Agence France-Presse
The Grace 1 supertanker
Sailing through the Strait of Hormuz, an Emirates-based oil tanker has vanished (from the radar). With the strait a flashpoint for US-Iran tensions, is Tehran to blame?

The Panamanian-flagged oil tanker Riah usually transits oil from Dubai and Sharjah to Fujairah, a trip of just under 200 nautical miles that takes a tanker like this just over a day and a half at sea. it reported its position off the coast of Dubai on July 7.

However, while passing through the Strait of Hormuz on Saturday night, the vessel's tracking signal abruptly turned off just before midnight, after it deviated from its course and pointed towards the Iranian coast. According to marine tracking data, the signal has not been turned on again since, and the ship has essentially vanished.

vanished tanker route hormuz
© Information from MarineTraffic.com and VesselFinder.com
A graphic shows the Riah's route and last known positions.
So what happened? With US-Iranian tensions bubbling, and Iran blamed for several attacks on oil tankers near the strait in recent months, attention turned to the Islamic Republic. Israeli media picked up the story on Tuesday, and framed it as another development in the ongoing saga, highlighting Iranian Supreme Leader Ayatollah Ali Khamenei's vow on Tuesday to respond to Britain's seizure of an Iranian tanker near Gibraltar earlier this month.

A spokesman for the shipping company that owns the Riah - Sharjah-based Mouj-al-Bahar General Trading - told TradeWinds that the ship had been "hijacked" by Iranian authorities. CNN reported that the US intelligence community "increasingly believes" the tanker was forced into Iranian waters by the naval wing of Iran's elite Islamic Revolutionary Guard Corps, but has not revealed its sources.

However, Tehran has not acknowledged the disappearance of the Riah, even to deny the alleged 'hijacking.' Nor has the US Fifth Fleet, which patrols the region and has seen its presence bolstered by B-52 bombers and thousands of troops in recent months.

Foreign provocation is another explanation that will likely be thrown around. In light of recent news, the idea that Iran would interdict a tanker is one that will be taken seriously, but the United States has had ample opportunity to take military action against Iran recently.

President Donald Trump said that he was "cocked and loaded" to strike Iran last month after Tehran downed an American spy drone it said was flying in its airspace, but ultimately called off the attack. In short, if either side wished for war, another provocation would likely be unnecessary.

With provocation unlikely and Iranian responsibility as yet unknown, there are other reasons why a ship might simply vanish. Israeli website TankerTrackers.com compiles reports of ships it believes are switching off their trackers to dock in Iranian ports and load up on oil, in violation of American sanctions. The site reported a Chinese vessel - the Sino Energy 1 - disappearing late last month near Iran, before reappearing fully loaded and heading the opposite direction six days later. It is currently passing Singapore en route back to China.

However, an Emirates-based ship is extremely unlikely to be trading oil with Iran, given the Emirates' political differences with Tehran and close alliance with Saudi Arabia, the world's second-largest oil producer and largest exporter.

Further complicating matters, an Emirati security official told local media that "the tanker in question is neither UAE owned nor operated, does not carry Emirati personnel, and did not emit a distress call. We are monitoring the situation."

With conflicting reports circulating and nothing concrete yet, the whereabouts of the Riah is as opaque as the crude oil it carries.