Crossing the Strait of Hormuz remains one of the most dangerous trips a ship can make. Missiles and drones threaten from the air. Under the surface, mines may be waiting.
"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.
"If you're a captain, you'd like to see evidence mines aren't present," he adds.
Why mines are such an effective weapon
Modern mines rest on the seabed and detonate when they detect an acoustic or magnetic signal, triggering a pressure wave that breaks the keel of a passing vessel. Others rise through shallow water, float, or are powered towards a target.
The technology is neither difficult nor costly. That is the whole point.
"Mines are a very cheap way of waging a naval war, as the Royal Navy is acutely aware," says Ian McFarlane, a naval architect at the French defence group Thales.
The change in who does the looking
Finding sea mines has traditionally been the job of specialist mine-hunting vessels crewed by around 80 sailors — people sent deliberately into the water they suspect is mined.
Increasingly the work is done by autonomous systems monitored from the shore. Those might need only 20 personnel, working shifts on land.
There is a second reason navies like this, and it is not about courage. NATO navies face serious recruitment and retention problems. Highly portable robot systems that need a quarter of the people are attractive for that reason alone, and it is worth being clear that crew shortage is doing as much to drive this as crew safety.
Not a new idea
The technology has been in development for 20 years. During the 2003 Iraq war the US Navy searched the seabed with a torpedo-shaped robot called the Remus 100, pinging with sonar at depths down to around 100ft and sparing divers a dangerous job.
What has changed since is not the concept but the autonomy: enough onboard decision-making that one shore team can supervise several machines instead of driving one.
Why this matters to a trading nation
Bangladesh imports almost all of its fuel by sea, and a large share of that passes through the same chokepoints. The cost of a mine threat is not measured in ships struck — usually none are — but in war risk insurance premiums, delayed sailings and freight rates, all of which arrive here as the price of diesel and the cost of a container.
That is why "evidence mines aren't present" is a commercial product as much as a military one. A robot that can produce that evidence quickly, without putting 80 people over a minefield, changes what it costs to keep a sea lane open.
What the robots still cannot do
Finding a mine is not the same as removing one. Disposal still means putting a charge next to it, which still involves a crewed vessel or divers at the final step.
The autonomous systems also have to be carried to the area and launched, so a ship is still in the picture — just further away from the part that explodes. That is a real gain, and it is narrower than "robots have taken over".
