Turning off a ship's tracking signal is what smugglers do. Now the U.S. military is telling oil tankers to do the same.
The U.S. sent a note to the shipping world this week. It lays out the help it has been giving ships in the Gulf.
The note says the U.S. has quietly walked ships through the Strait of Hormuz, and fought off threats along the way.
The strait sits between Iran and Oman. About a fifth of the world's oil moves through it.
The trick is simple, and a bit scary. Ships shut off the trackers that show where they are.
Then they follow a tight lane that hugs the coast of Oman. The U.S. opened that lane just for this.
These trackers are normally kept on for safety, so turning them off shows how risky the strait has become.
Going dark means Iran can't easily find them. The catch is a lane that runs just 800 meters wide in spots.
Picture driving down a tight alley with your lights off, while a Navy guard rides along the whole way.
The early results look strong. About 70 ships have made the trip in three weeks, and no threat has gotten through.
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A big share of the world's oil moves through here each day. So when fears about Iran grew, ship owners got nervous.
Insurers got wary of the route too, and that pushed costs up for everyone.
That fear can hurt as much as a real strike, since a slowdown in ships pushes prices up fast.
So the military stepped in to keep the oil moving, and it built the plan in two parts.
First, tankers from Kuwait, the UAE, and Saudi Arabia fill up in the Gulf. They run the strait with U.S. jets, helicopters, and warships nearby.
Then they hand the oil to other ships near two ports in Oman, Sohar and Shinas. That keeps it flowing without sending each tanker the whole way.
It's a slow, careful relay, and it lets the U.S. guard a short stretch instead of the whole route.
For investors, the strait is the thing to watch. Any sign the program is breaking down could push prices up.
Oil prices have already swung hard on each turn in this fight. This program is one more reason a single headline can move them.
The strait carries about a fifth of the oil the world burns, so the stakes reach far past the Gulf.
For now, the ships keep moving, and the oil keeps flowing.
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