In 1989 Director James Cameron's sci-fi film "The Abyss" featured the use of liquid oxygen which permitted a diver to reach extreme depths wearing a diving suit. Cameron did not invent this concept for the movie as the breathing of perfluorocarbons (PFCs) had been theorized, studied and eventually even tested years before. Today some of the leading hospitals are using PFCs for treatment of premature babies with remarkable success. PFCs studies have also been carried out by the Navy in the treatment of decompression sickness (DCS) on swine.
Now Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would allow a human to breathe "liquid air". The liquid would be contained in a closed helmet, just like the one Ed Harris' character used in the movie. The PFCs would fill not only the lungs but all the air cavities - ear, nose and sinuses. CO2 that builds up would be expelled through a mechanical gill attached to the femoral vein in the leg. The suit would allow divers to descend to depths far greater than possible now and not worry about DCS.
The practical use of PFCs, whether for the treatment of DCS or to extend depth ranges, is still several years away. But it does appear that sometime in the future divers may be taking specialty courses utilizing the science of "liquid air".
Link to the full article in The Independent.