Iran has tightened control over the Strait of Hormuz, forcing ships to coordinate their passages with Iranian authorities. Thailand reported that one of its tankers successfully passed after negotiations with Iranian representatives, while another is still awaiting approval.

Ship insurance has seen a dramatic price increase. War risk premiums, which previously amounted to 0.15 to 0.25 percent of a vessel's value, now reach 5 to 10 percent. For a large crude oil tanker worth around 100 million dollars, this means additional costs of several million euros per transit.

"Premiums have risen significantly following the escalation of events from February 28," said David Osler, financial editor of Lloyd's List.

Some companies are avoiding the strait entirely, but oil pipelines through Saudi Arabia and the UAE provide only a partial alternative. The bulk of global oil exports still depends on this critical maritime corridor.

Energy analyst Bill Farren-Price warned that continued disruption could cause serious supply shocks on global markets.