Epirus Unveils Leonidas H2O: A New Microwave Weapon to Stop Sea Drones Without a Shot Fired

In a major step toward transforming naval defense, US defense company Epirus has revealed a powerful new weapon that doesn’t fire bullets or missiles—but instead uses focused energy to disable threats at sea. Named Leonidas H2O, this high-power microwave (HPM) system is designed to neutralize small, fast-moving sea drones and even manned boats without causing explosions or physical destruction.

A Silent Defense Against a Growing Threat

The rise of unmanned surface vessels (USVs)—popularly known as sea drones—has added a new challenge for naval forces around the world. These small, low-cost boats can be packed with explosives and sent on dangerous missions, often too small or fast to be intercepted by traditional weapons.

Leonidas H2O targets exactly this problem. Rather than using force to sink or explode the vessel, it emits high-energy microwaves that fry the internal electronics, effectively shutting down engines, sensors, or communications—rendering the boat useless without harming people or causing collateral damage.

This makes Leonidas H2O especially ideal for crowded coastal zones or busy ports, where kinetic weapons like missiles or guns could pose risks to civilians, infrastructure, or cargo.

Field-Proven in Naval Trials

Earlier this year, the weapon was tested during the US Navy’s Advanced Naval Technology Exercise – Coastal Trident (ANTX-CT), a technology showcase focused on defending against emerging maritime threats. During the event, Leonidas H2O successfully disabled four different vessel engines, ranging from 40 to 90 horsepower, using only half its full power.

Even more impressive, the system was scaled down to one-third of its normal size during the test, and still managed to neutralize its targets from about 100 meters away. According to Epirus CEO Andy Lowery, this test proved that Leonidas H2O is not just a concept—but a combat-ready tool that can address a pressing capability gap in naval security.

Smart Tech with Real-World Impact

What makes Leonidas H2O stand out isn’t just its stopping power, but its software-defined and solid-state technology. This means the system can be updated through software, adapted to different missions, and scaled to fit on various platforms—from fixed coastal stations to mobile sea or land vehicles.

It also uses non-ionizing radiation, which is safe around fuel, ammunition, and personnel—adding to its appeal in sensitive operational environments.

The broader Leonidas family of microwave weapons has already seen development for land and air use. Variants have been mounted on Stryker armored vehicles and even drones. This sea-based version marks the latest expansion of a flexible and scalable platform, designed for the growing threats posed by drone swarms and electronic warfare.

Why It Matters Now

With conflicts like the Russia-Ukraine war and Red Sea tensions showcasing how unmanned boats are being used to damage warships and merchant vessels, interest in non-kinetic countermeasures like Leonidas H2O is rapidly growing. These systems offer a way to stop threats instantly, safely, and repeatedly, without running out of ammunition.

As the U.S. Navy and its allies face more drone-related challenges, Epirus’ microwave weapon could play a key role in protecting harbors, coastlines, and even ships at sea—while minimizing the risk of unintended damage.

In short, Leonidas H2O isn’t just another military gadget. It’s a sign that the battlefield—especially at sea—is changing, and energy weapons are stepping into the spotlight.