Posted by John Walker on April 12, 2001 at 22:51:33:
In Reply to: Immortal Diver? posted by tleemay on April 12, 2001 at 14:26:56:
Terry, how slow we are to changes in this sport. This list truly reflects just that. OK, I'm sorry but I did just what you told me not to do. Post late at night when I'm tired. Oh well.
In 1912 Leonard Hill demonstrated the benifits of staged decompression over a continuous ascent reduced DCS. As early as 1951 Bateman and Beinke predicted silent bubbles were present following most dive but where unable to detect them until 1968 by Spencer and Cambell after the advent of a device commonly known as a Doppler. They showed that silent bubbles where present with out DCS symptoms with this modern piece of equipment.
But in between that era (1959)Brian Hill took a bunch of Okinawian diver and extended their ascent times to 2/3rds of the US Navys table and introduced Deep Stops dramaticly reducing onset of DCS. In 1979 Yaunt and Hoffman looked at DCS manifestation in a different way. Rather than look at tissue group they looked at the number and the size of bubbles. As well as the ability for these bubble seeds to transport and defuse gas molecules. They found that since bubbles where most always present that it was important to limit the amount of bubles as well as regulate the size of the bubbles to create optimal offgassing benefits. This could be achieved by ascending slower as in deep stops. The make a model called the "Variable Permiability Model" which in the year 2001 is starting to gain popularity based from more current studies.
Richard Pile stumbled across relatively old news, but people (some people) did listen to him. And in my opinion if we stop the study of diving history we will become stale divers. This has nothing to do with "DIR" perse. It's just that diver who are considered "DIR" pay attention and grow with the sport. They refuse to become stale divers.
Your BBS PAl,