Graham Hawkes—the submersible designer responsible for the advent of so-called underwater flight and the Super Falcon winged submersible—has debuted his latest design. Like the Super Falcon and Hawkes’s previous subs, the DeepFlight Dragon is positively buoyant, so it will float to the water’s surface unless the thrusters are engaged to submerge it. Both the Super Falcon and the Dragon are powered by a zero-emission electric motor that will take them as deep as 400 feet—an area sometimes called the edge of dar…