Asked by Le Monde, Vincent Clerc, chief executive of Danish shipping group Maersk, says that ten of the company's 700 vessels are currently stuck in the Persian Gulf. "Our first task was to secure our 6,000 staff on the ground and our ten vessels stranded in the Gulf. The latter are grouped in the middle of the sea, because it is a safer place than ports, which are being attacked," he says.

For now, oil inventories remain sufficient in the United States, Europe or South America, but Asia remains highly dependent on flows from the area, which could lead to a drying-up of bunkering points in the region. "If we do nothing, we risk finding ourselves, in Asia or the Middle East, with supply points running dry," the executive warns.

To keep its operations going, the company must charter tankers to move fuel between continents, sometimes relying on road transport from alternative ports such as Jeddah or Oman.

"All this logistics comes at a cost. In addition, dozens of our ships have to take shelter in ports that were not on their rotation and we have to mobilise trucks to move containers to their final destination. We do not just leave them in the first port we come to and then sail away again, as some of our competitors do."

Restrictive clauses at insurers

In these conditions, Jefferies reports that insurance premiums have also risen sharply, which helps explain why many ships remain stuck in the Gulf. The DFC (US International Development Finance Corporation) has also announced a proposed reinsurance facility intended to support the "Marine War Risk" insurance market, covering up to $20bn in potential losses.

"Most shipowners operating in the Persian Gulf have probably had to reinstate their insurance policies after their initial cancellation, but at significantly higher rates," Jefferies says.

Insurers are also said to have introduced restrictive clauses, which could in particular exclude or make more expensive passages through the Strait of Hormuz. "These conditions could explain why only one ship is said to have crossed this passage since the start of the conflict," the analysts say.

At around noon, Maersk shares were down 0.15% and were showing a weekly decline of 4.3%. Since the start of the year, however, the stock has posted a gain of around 11%.