In an effort to respond to increased threats posed by Russian and Chinese stealth ships, the U.S military has come up with a not-so-simple, but nonetheless elegant solution: a robotic ghost ship that will follow enemy stealth vessels across the ocean. It makes sense; you can’t hide if you’re being tailed every step of the way.

Earlier this year, the Defense Advanced Research Projects Agency announced that its 132-foot anti-submarine warfare continuous trail unmanned vessel, or ACTUV, passed a series of tests along a 35-nautical mile stretch of water off Mississippi. The boat was able to follow a target without crashing into rocks or behaving erratically, which is pretty impressive when you consider that there’s no one at the helm.