The Navy also employs underwater drones that use side-scanning sonar emitters to map the seafloor.
Typically, Navy divers will program the coordinates of a search grid into self-propelled torpedo-like devices called autonomous underwater vehicles, then carry them in small boats to place them in the water. From there, the vehicles steer themselves, maintaining a steady distance above the seafloor and blasting out sonar waves to locate any mines.
After the vehicle is hauled back aboard a boat or mother ship, its data is pulled into a computer that stitches it all into a single image that can be quickly scanned to identify any objects that look like they could be mines.
If any suspicious items are seen, the divers would likely return to the site and investigate further with a remotely operated vehicle — or ROV — that they can steer directly to the object using video cameras. Many of these ROVs have gripper arms that can place explosive charges onto any objects found to be mines.
Barring that, things can get more personal.
Navy explosive ordnance disposal technicians using special equipment to cut down on noise, bubbles and even their magnetic signature, dive down to the suspected mine. In the murk, hand-held sonar devices help them locate the target, which they can either neutralize and bring back to the surface — to exploit any intelligence value — or place demolition charges to destroy the mine after they leave the water.
Dives on so-called “influence fired” mines, which use a combination of magnetic, seismic, pressure and acoustic sensors and sit on the seafloor waiting for ships to pass, are by far the most dangerous. It is the only scenario in which U.S. military divers are trained to dive alone and without any kind of line or buoy tied to them — the thought being that it is better to lose one sailor than two if the mine explodes.
During mine-clearance operations after the 1991 Persian Gulf war, explosive ordnance disposal technicians who dove on influence-fired bottom mines received Bronze Stars for valor in recognition of the extreme hazards they faced.
Pentagon and other U.S. officials said on Monday it was too early say what would happen after Friday’s scheduled signing ceremony to the more than 50,000 U.S. troops assigned to the Iran mission. They are scattered throughout the Middle East, Europe and the United States.
Most of those forces, as well as two aircraft carriers and scores of fighter jets in the Middle East, are expected to stand ready for at least several more days while Trump administration officials assess whether the initial deal to reopen the strait holds.
If it does, the Pentagon is likely to begin quietly redeploying thousands of troops, including soldiers from the Army’s 82nd Airborne Division, special operations commandos and some Navy ships. But if fighting resumes or the deal otherwise looks shaky, U.S. forces are likely to stick around longer.
“We’ll make sure the military option is there,” the defense secretary, Pete Hegseth, told CBS News’s “Face the Nation” on Sunday. “That military might will stay as long as necessary.”
Eric Schmitt contributed reporting from Washington.
