What It’s Like to Steer a Giant Tanker Through the Strait of Hormuz

John Smith is trying to get some rest, but he’s nervous. In a few hours, he’ll navigate his 1,100-foot tanker—a vessel and cargo that together are valued at well in excess of $100 million—through the world’s most important, and lately most dangerous, chokepoint for global energy flows. “There will be six of us on the bridge looking out for ‘fast boats’ approaching,” says Smith, whose name was changed to protect his security, writing by email from his ship. “Not sure six people on the bridge will have any deterrent effect on troops abseiling down onto the ship from a helicopter. All on board are nervous of the situation. Also of course the families at home.”

At the time he emailed, Smith’s ship, one of the world’s largest, still had eight hours before it made it through the Strait of Hormuz, a waterway linking the oil-rich Persian Gulf with global markets. A third of the world’s seaborne petroleum, and a huge volume of liquefied gas, pass through the strait every day. On July 19, Iran seized a U.K.-flagged tanker there in an apparent retaliation for Britain’s Royal Marines helping to arrest a vessel transporting Iran’s crude in the Mediterranean earlier in the month in an alleged violation of Syria sanctions.