Shipping companies are taking a cautious approach to sending vessels through the Strait of Hormuz after signs that some kind of reopening of the vital oil channel might be possible.

Iran’s Islamic Revolutionary Guard Corps said on May 6 that with “new protocols in place, safe, stable passage” through the waterway will be ensured. That came soon after it emerged that the U.S. had proposed a peace deal that Tehran is now considering.

Five industry executives, including shipowners, vessel managers and security consultants, said that it was too soon — and too unclear — for crossings to resume. Two cited an attack on a container ship on May 5 as one reason to be wary. 

International shipping association Bimco said it would need official confirmation of any new rules of transit before issuing any update of its safety guidance.

“The shipowners I’ve spoken to have said they’ll believe it when they see it,” said Halvor Ellefsen, a London-based director at Fearnleys Shipbrokers UK Ltd. “It’s not the first time there have been public statements that were encouraging, only for them not to materialize.”

The reopening of Hormuz is critical for the global oil market and the wider economy. Its effective closure has choked off millions of barrels of supply, and driven a surge in prices. U.S. gasoline this week topped $4.50 a gallon for the first time since 2022. 

It’s still possible some shipowners will view the IRGC pronouncement as an opportunity to attempt passage. There was caution the last time there were signs of an easing of tensions, and yet multiple commercial vessels did attempt transit, only to U-turn when it became clear the waterway remained unsafe.

There was no immediate uptick in traffic observed on May 6, although any increase can take a few hours to emerge in ship-tracking data.