Strait of Hormuz threat level downgraded after Iran deal, says U.S.-led maritime security group

The threat to ships transiting the Strait of Hormuz has lessened following the announcement of the Iran deal, a naval coalition led by the United States told shippers in a notice this week.

The Joint Maritime Information Center downgraded the threat level in Hormuz to "substantial" from "severe" in an advisory note published Tuesday. The center is a maritime security organization headquartered in Bahrain that coordinates among allied navies and merchant ships in the Middle East.

Shippers should nevertheless remain aware that "an attack is still a strong possibility" when navigating the strait, the JMIC said in its notice. Mines also remain a threat and "caution is advised on all approaches."

But the behavior of Iran's Revolutionary Guard "has become less volatile" following the announcement of the U.S.-Iran deal, the JMIC said. The U.S. Navy continues to "provide stabilizing oversight," according to the notice.

Oil tanker traffic through Hormuz has not significantly increased since the U.S. and Iran announced the deal on Sunday. Six tankers and 13 commercial ships transited Hormuz on Tuesday, according to data shared by Kpler. More than 100 vessels sailed through the strait daily before the war.

"Strait of Hormuz traffic remained significantly reduced," the JMIC said in its Tuesday notice.

The security situation in Hormuz was classified as "critical," the highest threat level issued by the JMIC, as recently as June 4. The CEO of oil tanker company Frontline told CNBC last week that some shippers were waiting for the threat level to be downgraded before transiting the strait.

"When some of these red lights become orange or yellow, you're going to see a fairly quick move of owners starting to call and go through the Hormuz Strait," said Frontline CEO Lars Barstad.

The U.S.-Iran deal promises to open Hormuz to commercial ships and lift the U.S. naval blockade of Iran. Washington and Tehran are scheduled to formally sign the deal Friday in Geneva, Switzerland.

Traffic through Hormuz plunged after the U.S. and Israel attacked Iran on Feb. 28. Tehran retaliated by targeting ships sailing through the strait, effectively closing the sea lane and triggering the biggest oil supply disruption in history. About 20% of global oil supplies passed through Hormuz before the war.

The global shipping trade group Bimco said Monday that "credible assurances" are needed from Iran and the U.S. before traffic through Hormuz can return to prewar levels.

"Due to lack of details and a history of overly optimistic reassurances, we believe the security situation for the shipping industry remains volatile, and we still consider it very risky for ships to commence transits at this point," said Jakob Larsen, chief safety and security officer at Bimco.

"The threat of mines in the area remains a concern immediately as well as further down the line and mine-free routes need to be established," Larsen said.