For four months, largely hidden from public view, small teams of U.S. Navy divers and special operations personnel carried out one of the most dangerous underwater missions of the year: searching for and destroying naval mines in the Strait of Hormuz.
The operation unfolded mostly at night, amid an active confrontation with Iran and under conditions in which a single mistake could have been fatal. Instead of relying solely on conventional minesweepers, U.S. forces reportedly used inflatable boats, unmanned surface vessels, underwater systems and high-resolution sonar to search the seabed for explosives.
The technology could identify suspicious objects and dramatically reduce the amount of time human operators had to spend in the danger zone. But technology could not eliminate the need for people altogether.
Once a mine was located, someone still had to make the final decision about how to neutralize it. In some cases, that meant sending a diver into the water to approach an explosive device and attach a demolition charge.
Retired U.S. Navy Captain Bill Hamblet described the process to the Financial Times in stark terms: after detection, “a navy diver” may have to enter the water, approach the mine and place a charge on it.
That final step transformed an already difficult technological operation into something far more personal.
The diver was no longer controlling a robot from a safe distance. He was physically entering an underwater environment in which visibility could be limited, currents unpredictable and the object ahead potentially capable of destroying a ship.
As Chatham House analyst Nitya Labh has emphasized, mine clearance is an extremely time-consuming undertaking. In an interview cited in reporting on the operation, she characterized the work as essentially the active detonation of bombs underwater.
The mission mattered because of where it was taking place.
The Strait of Hormuz is not simply another shipping lane. It is one of the world's most important maritime chokepoints, connecting the Persian Gulf with the Gulf of Oman and the Arabian Sea. According to the U.S. Energy Information Administration, approximately 20.9 million barrels per day of crude oil, petroleum products and other liquids moved through the strait during the first half of 2025—equivalent to roughly one-fifth of global petroleum liquids consumption and more than one-quarter of global seaborne oil trade.
A prolonged closure or even uncertainty over the safety of the route can therefore reverberate far beyond the Middle East.
It can affect tanker schedules, insurance premiums, fuel prices, refinery supplies and the calculations of governments thousands of miles away.
That is why the underwater campaign was more than a military cleanup operation. It was an attempt to restore confidence in a maritime artery upon which the global economy depends.
A Chokepoint the World Cannot Easily Bypass
The geography of Hormuz explains much of its strategic importance.
The strait lies between Iran to the north and Oman and the Musandam Peninsula to the south. At its narrowest, the waterway is only about 21 miles wide. Yet it provides the principal maritime outlet for some of the world's largest oil and gas exporters.
Saudi Arabia, Iraq, Kuwait, the United Arab Emirates, Qatar and Iran all depend to varying degrees on routes connected to the Persian Gulf.
There are alternative pipelines, but their capacity is limited compared with the volume normally carried by tankers. The EIA estimates that Saudi Arabia's East-West pipeline and the UAE's Abu Dhabi pipeline together can provide several million barrels per day of bypass capacity—only a fraction of the volumes that normally transit Hormuz.
The strait is also important for liquefied natural gas.
Qatar, one of the world's largest LNG exporters, relies heavily on the waterway to reach international markets. The EIA has estimated that roughly one-fifth of global LNG trade has historically passed through Hormuz.
This makes the waterway unusually difficult to replace.
If one major shipping route is disrupted, vessels can sometimes take a longer route around a continent or through another canal. Hormuz presents a different problem: there are alternative pipelines and routes, but they cannot simply absorb the entire volume overnight.
The result is that even a relatively small physical threat can generate an enormous psychological and economic effect.
A tanker operator does not necessarily need to see a mine explode to decide that the voyage is too risky.
The mere possibility that a minefield exists can be enough to alter shipping patterns.
The Minefield
During the conflict, Iran was reported to have laid mines in or around established shipping lanes in the Strait of Hormuz.
By June, maritime authorities and shipping organizations were warning that roughly 80 mines were believed to be present in the central shipping area. The Guardian, citing tanker owners' association Intertanko, reported that the principal traffic route through the center of the strait was considered unsafe and that clearing such a number of mines could take considerable time.
The exact number and locations remained uncertain.
That uncertainty is itself part of the problem.
Chatham House reported that Iran had not publicly confirmed how many mines it had laid or precisely where they were located. Analysts estimated that around 80 mines could be present, including Iranian-made Maham-series mines. According to the think tank, these weapons can be particularly difficult to detect because their characteristics complicate conventional sonar searches.
A minefield does not have to resemble a wall of explosives.
Mines can be separated by significant distances. Some may be moored beneath the surface, while others can rest on or near the seabed. Depending on their design, they can be triggered by magnetic, acoustic, pressure or other signatures associated with passing vessels.
For a tanker captain, therefore, the question is not simply, “Where is the mine?”
It is also:
Where are the mines we have not found?
That is one reason maritime mine clearance is so slow.
Clearing a channel requires confidence not only that individual mines have been destroyed, but also that the search itself has been sufficiently thorough.
Why the U.S. Used Robots Before Divers
The reported U.S. operation illustrates how modern mine warfare increasingly combines autonomous technology with human expertise.
According to the Financial Times, U.S. teams used unmanned surface vessels and specialized underwater systems equipped with high-resolution sonar to search the seabed. Small groups of divers operated from inflatable-hulled boats, frequently under cover of darkness.
The basic logic is straightforward.