Researchers at MIT have developed a submersible robot approximately the size and shape of a football. The intention is to have these machines use ultrasound to scan the hulls of ships in port for any kind of contraband.

Two halves make up the device: a solid, non-permeable top to house the electronics, and a bottom half that contains the propulsion systems. The bottom needs to let water pass through as the robot sprays that water from a series of tubes to move and maneuver beneath the surface. This method of propulsion is, in fact, a big advantage over current remote operated mini-submersible robots, as it leaves no air bubbles behind. In theory, this means that port authorities could scan ship after ship without alerting those on board in any way.

So far, these trials are in their beginning stages, and the design has some limitations. The device works by pressing a flat surface on its top half against a ship’s hull and sliding along it. Indeed ultrasound must have a consistent distance from the target to function properly; however ships hulls are rarely that smooth. They get crusted with barnacles and debris that would make the robots operation impossible in its current form. According to MIT News, however, the device’s creators are experimenting with mechanisms to provide the proper buffering distance (“a specific multiple wavelength of sound”).

Now the initial prototype only has a battery life of about forty minutes, but the next generations are planned to be wirelessly chargeable. Couple this with the fact that many of the machine’s parts were 3D printed, and port authorities may soon have remote operated scanners which charge without leaving the water, all built for as little as $600. If that price is achievable, it’s easy to imagine small fleets of these robots scanning ports around the globe.