Watch this robotic fish flap its fins in Fiji's Rainbow Reef

It looks and moves like a real fish, flapping its tail from side to side. But this fish is controlled by a human diver via a waterproofed Super Nintendo controller and an ultrasound transmitter. SoFi, the soft robotic fish, has been designed to let researchers study marine life up close. Remotely-operated or autonomous submersibles are usually propeller-driven, which tends to disturb wildlife. Videos of test dives in Fiji's Rainbow Reef show SoFi skirting over coral alongside real fish, which seem unfazed by the mechanical interloper.