There’s a lot of ground between puttering around with your face strapped to a snorkel and managing the dangers, equipment, certification and expenses of scuba diving. Surface-supplied diving systems fill some of this space by strapping you to a breathing hose that plunges deeper than a snorkel but without some of the complications of scuba. Typically these systems rely on some form of compressed air, but a new prototype from Austria uses a more sustainable air supply: you. The ExoLung translates the diver’s swimming motions into air movement, keeping breathing air flowing so long as the diver keeps swimming.
Like other surface-supplied diving systems, the ExoLung has a buoy that floats on the surface of the water, serving both as a safety restraint and air intake. A hose connects the buoy with the water bell worn on the front of the torso. Inside the bell’s hardshell body, a collapsible water bladder is attached to leg straps that secure around the diver’s feet.
As the diver extends his or her legs, the straps pull the bladder, sucking in air as water is pushed out. Upon leg compression, the straps relax and water pressure fills the bladder back into the hardshell body, compressing the air for inhalation.
Other surface-supplied and portable breathing hardware that fills the gap between snorkelling and scuba diving is limited by the constraints of battery power or compressed air tanks. The Indiegogo-funded AirBuddy system advertises up to 45 minutes of lithium battery power, while the cylinder-supplied Scorkl breathing mask that hit crowdfunding around the same time in 2017 offers only 10 minutes.