U.S. officials said on March 11, 2026 that Iran had laid mines in the Strait of Hormuz, the narrow waterway that carries 20% of the world’s oil exports from the Persian Gulf to the rest of the world… A U.S. military website describes one class of Iranian mine, the Maham 1, as a circular piece of 1980s-era equipment designed to float in water as shallow as one meter that is equipped with five horns that when struck can detonate up to 120 kilograms—equivalent to 264 pounds—of explosives. The mines are moored on a chain or anchored to the seabed.

The U.S. military said it has destroyed Iranian naval vessels designed for setting mines…Yet Iran primarily sets mines using frogmen on small boats that resemble ordinary fishing vessels, an informal maritime militia of dinghies that is virtually impossible to identify and eliminate.  Iran also has an arsenal of limpet mines that divers can attach to the hulls of ships magnetically or with a nail gun.

Excerpt from James T. Areddy et al., Iran’s Sea Mines Are One of Its Most Powerful Weapons, WSJ, Mar. 11, 2026