In a wave tank at a robot laboratory in the Scottish capital Edinburgh, engineers observe in silence as an underwater drone rises stealthily to the surface. The team, which led the development of the remotely operated vehicle (ROV) at Heriot-Watt university, believe the submersible machine is a game-changer for offshore wind farms, obviating the need for divers. The engineers reckon it will soon be ready to perform inspections and maintenance at wind farms, transforming the nature of t...