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March 31, 2008

Free diving

When I think of diving, I think of breathing underwater. But most of us dive long before we learn how to use Scuba. When I was a kid, diving to me meant getting to the ten-foot bottom of the public pool, and it made my ears hurt. For a while I practiced breathholding and timed myself. I can't remember how long I managed to go without taking a breath, but it seemed respectable to me back then. I never did learn how to equalize my ears free diving. At Three Sisters in Crystal River, Florida, a sharp pain in my ears kept me from going deeper than eight or ten feet or so. Yet, free divers go much, much deeper than that.

I just finished reading "The Dive -- A Story of Love and Obsession" by Pipin Ferreras. It's the story of a Cuban free diver who set record after record together with his wife, Audrey. A fatal accident killed Audrey during a dive to 170 meters (558 feet) and the book recalls Ferreras life and is also a tribute to his wife. Earlier I had read "The Blue Edge" by Carlos Eyles, also a man who pretty much dedicated his life to free diving, albeit for different reasons. But whether it is records, spear fishing, or just being one with the sea, it is hard for me to imagine how it is done.

Scuba and free diving both take place in the water, but beyond that everything seems different. Scuba dives can take an hour or more. Free dives a couple of minutes or maybe three for accomplished free divers. Scuba is slow and measured movement; free diving means darting down and back to the surface. Scuba means dealing with the gas laws so as to avoid embolisms, narcosis, the bends; free diving has none of that as no additional nitrogen is introduced into the body.

Competitive free diving, of course, has its own rules and governing bodies. There are different categories. In "Constant Weight" the diver follows a line to a certain depth and then swims back up, all on his or her own power. In "Variable Weight" the diver uses a weighted sled to go down, then swims back up. In "No Limit," the diver uses a sled to go down, then inflates an airbag at the bottom and holds on to that to get back to the surface. The depths reached are almost unimaginable. How can they do that?

Apparently, in free diving the rules are all different. With no compressed air to counter-balance the enormous water pressure, the lungs and other air cavities inside the body compress enormously. Conventional equalization of the ears and sinus only goes that far; beyond a certain depth the divers do "water equalization, " i.e. they let salt water into the sinus system in a practice that is described as entirely unpleasant. And another phenomenon takes place when a "blood shift" keeps the lungs from collapsing. It's a residual from ancient times perhaps, from our genetic past, but it works (not that I'd ever want to experience it).

The kind of free diving described in "The Dive" requires extensive planning and preparation. Safety divers on scuba are deployed at regular depth intervals, including the bottom. In those extreme record attempts, that means a diver has to wait at almost 600 feet on Trimix. Breathing gas goes very fast at that depth and it's clear that timing is everything. Once the safety divers are down, the free diving attempt must be made exactly on time. And even so, the deeper safety divers won't be back on the surface to partake in the celebrations as there are hours of decompression time.

Wherever there are records and titles, there are politics and competing agencies and bodies, and apparently that's no different in free diving. In his book, Ferreras describes his life and career, and his intense personality that more or less made him an outcast. Already relying on his own certifying agency, after his wife died in her record attempt he came under intense criticism. One of his own crew wrote a book accusing Ferreras of negligence and wrongdoing.

Knowing my tendency to get deeply involved in topics that interest me, I promised myself not to start research on free diving after I finished the book. But in this day and age that's hard to do. Wiki provides an overview, and Audrey Mestre's final dive is right there on YouTube. Yes, the sled's camera recorded how she is trying to inflate the lift bag at a depth of 558 feet, and it won't inflate. You can watch the whole thing.

Posted by conradb212 at March 31, 2008 03:37 PM

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