The U.S. military has a growing history of adapting biological traits to robotic designs, including a "cheetah" robot that can run up to 30 miles per hour and equipment-carrying robots that basically look like headless, metal horses. So it makes sense that the same approach would be taken for robots designed to go in the water, and that's just what the Navy has done with GhostSwimmer.
OK, so it's not exactly a "robot shark," in that it's not a predator, it doesn't have teeth and we probably won't have to call in Chief Brody to blow it up, but GhostSwimmer was designed to move and look like a real fish. The 100-pound, 5-foot drone was developed by the Chief of Naval Operations Rapid Innovation Cell and Navy contractor Advanced Systems Group at Boston Engineering, and though it was modeled after an albacore tuna, as you can see above, you'd be forgiven if you mistook it for a shark.
Just like a real fish, the GhostSwimmer uses its tail to propel and steer itself, and it comes with pectoral and dorsal fins. It's capable of operating in 10-inch shallow water, can dive as deep as 300 feet, and can either swim independently or be controlled via a 500-foot tether. GhostSwimmer is part of new Navy experimentation on unmanned vehicles that can work underwater, and reportedly just completed its testing phase.
So, what will the robot be used for? Well, like many drones, it could eventually be used for surveillance and reconnaissance, and its fishlike design would go a long way in making it hard for enemies to spot, but it's got plenty of other uses too. The GhostSwimmer could also be deployed to check the hulls of ships for damage, and it could even replace trained dolphins and sea lions on missions to help the Navy locate mines and carry gear. We still don't know how much the drone will cost, or whether or when it will see action, but it does seem like a versatile new addition to the military.
So maybe we shouldn't be scared of the robot shark after all ... at least until someone mounts a laser on its head.