Insuring vessels to sail through the Strait of Hormuz is still possible, even if at a very high cost, according to people involved in the market.

The cost of coverage has leaped to about 5% of the value of a ship, roughly five times the level seen in the earliest days of the Iran war, and an even larger multiple of the fractions of a percentage point seen in periods when there’s relatively little conflict, the people said, asking not to be named discussing private information. That means insuring an oil tanker worth $100 million would cost about $5 million.

While the rates are high, it’s also a sign that cover remains available for the handful of vessels looking to cross the vital waterway that usually accounts for a fifth of the world’s oil and liquefied natural gas shipments. A major question is whether ship owners are willing to do that, given the safety risks. 

Asked why the U.S. cannot immediately reopen the Strait of Hormuz if Iran’s mine-laying ships are destroyed, President Trump said on March 16 that vessels have to be willing to pass through the waterway for normal operations to resume. 

Details of a plan for the U.S. International Development Finance Corporation to help insure tankers are still unclear. The U.S. has announced a $20 billion reinsurance program to help revive shipping through Hormuz. Insurers have expressed interest in partnering with DFC to offer the reinsurance, an agency official said last week. Trump’s push for allies to help secure the waterway has been met with reluctance.

So far, most of the insurance rates are being quoted for vessels with links to China, India or Pakistan, one of the people said. Insurers in the London market have insisted that cover remains available for vessels in the Middle East and that it is not a factor prohibiting trade into and out of the region. 

The U.K. Maritime Trade Operations Center estimates that at least 20 ships have been involved in security incidents since March 1 in and around the Persian Gulf. The most recent of those was March 12, when a container ship was struck, causing a fire.