Naval mines pose a major threat to ships in the Persian Gulf during the war with Iran. Clearing and deactivating them is risky. So far, underwater drones can only do part of the job.
Against the backdrop of the war with Iran, more than a dozen countries agreed on Friday (April 17) in Paris on an international mission to secure the Strait of Hormuz after the fighting ends. Federal Chancellor Friedrich Merz hinted in Paris at the Bundeswehr’s participation in mine clearance and maritime reconnaissance.
RISK TO MERCHANT SHIPS
The Persian Gulf and the surrounding region remain a danger zone for commercial shipping. Risk factors include not only a possible attack by the warring parties, but also threats that may be lurking beneath the surface of the water. In early April, Iran’s Revolutionary Guards announced that the leadership in Tehran had ordered the strait to be mined. “We don’t even know for sure whether there are actually mines there, but the constant risk is enough. In a war zone, no one can currently verify this,” says Johannes Peters, director of the Department for Maritime Strategy and Security at the Institute for Security Policy at Christian-Albrechts University in Kiel.
SEA MINES AND OPERATION
Naval mines were used in the First and Second World Wars. At that time, they were anchored mines: a rope was attached to the seabed by a weight, while a sphere with a detonator inside floated at its upper end. When a ship or submarine collided with these detonators, the mine exploded. Activation by direct contact was the mode of operation at that time. “Modern mines have little to do with this type of mechanism,” Peters told DW. Mines are still anchored to the seabed today. As a means of naval warfare, they are intended to give one warring party control over a certain area.
“For this reason, they have to be fixed in a certain place,” explains Peters. But activation is no longer done through direct physical contact.
Modern naval mines operate by being activated by pressure waves, electromagnetic signals or sound waves. Each type of ship has its own pressure, electromagnetic or acoustic signaling system, so it emits different signals. Mines can be programmed in such a way that, for example, they only react to the sound waves of a certain type of ship. “With the help of submarines, the acoustic signal of enemy ships can be determined,” says Peters. Based on this, the mines are then programmed. “So enemy ships activate the mines with their acoustic signals, while with their own ships they can move without problems through the mined area,” explains the expert.
MINE CLEARANCE
So-called mine hunting, i.e. When a suspicious object is located, it must first be determined whether it poses a threat. If this is verified, it is always decided individually what to do with the explosive device. Should it be removed first? Should the mine be deactivated underwater or detonated in a controlled manner? This dangerous task can be carried out by specially trained military personnel – a kind of “underwater explosive ordnance disposal service”, as Peters calls it. Sometimes, this is even possible without risking human lives. “When possible, we use drones to identify and destroy the objects we find,” Mykola, a soldier with a Ukrainian naval mine clearance unit in the Black Sea, told DW earlier this year. The Russian Navy has mined the Black Sea as part of Vladimir Putin’s aggressive war against Ukraine.
DRONE AGAINST NAVAL MINE
The German Navy is also now using drones for mine clearance. “We mainly use autonomous systems for seabed control,” said Frigate Captain Andreas from the 3rd Minesweeper Squadron of the German Navy, who we will only mention by name for security reasons. “Previously, ships equipped with sonar would fly directly over minefields for this purpose.
Thanks to unmanned systems, it is no longer necessary to expose 40 people to direct danger.” This does not mean that human personnel are no longer needed. Drones send images of the seabed, which then have to be analyzed. What is just metal debris and what is a truly dangerous sea mine? This decision – as well as how to handle the explosive device – is still being made by humans.
USE OF DRONES IN THE STRAIT OF HORMuz WITH DIFFICULTY
The drones currently used by the German navy cannot stay at sea for very long due to their limited battery life. This means that they have to be “deployed” relatively close to the area they are supposed to monitor. “You always have to be very close,” says frigate captain Andreas. “In a sensitive environment like the Strait of Hormuz, that would be difficult. Iran has long-range capabilities and we have to protect our personnel.”
DRONI “GREYSHARK”
Meanwhile, various companies are already working on developing drones that can operate for longer periods. One of them is the company Euroatlas from Bremen in northern Germany. Their underwater drone “Greyshark” can currently move at sea for about six hours at a speed of ten nautical miles, while at a speed of four miles it can stay underwater for three times longer. In September 2026, series production of the battery-powered version is expected to begin, while series production of a “Greyshark” drone with a gasoline engine is planned for the end of the year. This version is expected to be able to operate autonomously at sea for several weeks.
“In the Strait of Hormuz, surface ships are at risk from land-based weapons strikes, and this also applies to mine-sweeping vessels,” says Markus Beer from the autonomous systems sector at Euroatlas.
“Underwater, reconnaissance work [by drones] would be possible without risk, without escalating the situation.” And what’s more: the Greyshark can be launched into the water from a safe distance. “The small drones used today for mine hunting only have a few hours of autonomy. The Greyshark can travel much further,” Beer told DW. In addition, the drone takes high-resolution images and is able to identify objects it detects on the seabed itself.
The German Navy, as well as other nations, already had the opportunity to form an impression of the capabilities of the “Greyshark” during the NATO maneuver REPMUS 25, which took place last September off the coast of Portugal. (DW)