Into the abyss: The diving suit that turns men into fish

The invention of scuba diving has allowed us humans to breathe underwater but only at very shallow depths.

This is due to our inability to conquer the bends, diving below 70m still remains astonishingly dangerous to anyone but a handful of experts. Ultra-deep diving is so lethal that more people have walked on the moon than have descended below 240m using scuba gear.

However an inventor in the United States believes he has solved the problem of how to get humans down to before unthinkable depths – by getting us to breathe liquid like fish.

Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would allow a human to breathe “liquid air”, a special solution that has been highly enriched with oxygen molecules.

The idea immediately conjures up the terrifying spectre of drowning but our lungs are more than capable of taking oxygen from a solution.

“The first trick you would have to learn is overcoming the gag reflex,” explains Lande, a 79-year-old inventor from St Louis, Missouri. “But once that oxygenated liquid is inside your lungs it would feel just like breathing air.”

Lande envisages a scuba suit that would allow divers to inhale highly-oxygenated perfluorocarbons (PFCs) – a type of liquid that can dissolve enormous quantities of gas. The liquid would be contained in an enclosed helmet that would replace all the air in the lungs, nose and ear cavities.

The CO2 that would normally exit our body when we breathe out would be “scrubbed” from our blood by attaching a mechanical gill to the femoral vein in the leg.

By using oxygen suspended in liquid, divers would no longer have to worry about decompression sickness – the often fatal condition known as “the bends” which occurs when nitrogen dissolved in the blood under the immense pressures of deep water bubbles out as we rise. It could potentially allow them to descend to far greater depths than is currently possible.

Currently the only way divers can work for long spells in the deep is either from the safety of robotic vessels and submarines; or by using saturation diving, an incredibly complicated technique where divers have to be brought up to the surface in a pressurised container over a matter of weeks.

With saturation diving, the deepest anyone has gone is 701m. Using scuba equipment the record is 318m, set by the South African diver Nuno Gomes in June 2005. It took him 14 minutes to descend and 12 hours to come back up to the surface.

The reason for these slow ascents is our reliance on compressed gasses to breathe in water. Under the incredible pressure exerted by billions of tonnes of ocean, gasses like nitrogen and helium dissolve into our bloodstream, much like CO2 is dissolved in a soda bottle.

Ascending towards the surface is like opening that soda bottle – the gas comes out of solution and into our bodies. If we don’t give our bodies enough time to expel those gasses by ascending slowly, we die.

“The beauty of doing it all from a liquid is that you don’t have to use these highly compressed gasses in the lungs that are going to dissolve into the blood,” says Dr Lande, who recently presented a paper on his patent to the first International Conference on Applied Bionics and Biomechanics in Venice. “You have a liquid that you can infuse just as much oxygen as you need.”

Shaffer has previously experimented with animals and PFCs at depth and found the technique to work. “I have personally put mammals down to a simulated depth of 1000 feet and then decompressed them in half a second and they have no decompression sickness,” he says.