Traversing the Strait of Hormuz remains one of the most dangerous trips a vessel can take.
Despite assistance from the US Navy, ships are still being attacked.
“To transit the Strait of Hormuz you need agreement between the captain and the crew to take the risk. You need war risk insurance. And the captain has to make the final decision,” says Steve Cameron, a former merchant navy officer and maritime consultant.
Missiles and drones are a threat from the air, but under the surface mines may also be lurking.
“If you’re a captain, you’d like to see evidence mines aren’t present,” Cameron adds.
Modern mines rest on the seabed and detonate when they detect an acoustic or magnetic signal, triggering a pressure wave that will break the keel of a passing vessel.
Others can rise through shallow waters or float, or be powered towards a target.
The technology itself is not difficult or costly, but the mere threat can stop a tanker fleet from sailing.
Ian McFarlane of French defence group Thales is a naval architect who knows mine warfare well. “Mines are a very cheap way of waging a naval war, as the Royal Navy is acutely aware,” he says.
Finding sea mines has traditionally been the job of specialist mine-hunting vessels, with crews of around 80 sailors.
To keep humans out of harm’s way, an increasing amount of the work is done by systems that are autonomous and monitored from the shore.
They might only need 20 personnel, working in shifts on land. With the recruitment and retention challenges facing Nato navies these highly-portable robot systems are very attractive.
Such tech has been under development for 20 years.
During the 2003 Iraq war the US Navy poked around the seabed looking for mines with a torpedo-shaped robot called the Remus 100.
Pinging around with sonar these little machines operated down to around 100ft depth and spared divers a difficult and dangerous task.
