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Date: Thu, 11 Oct 2001 06:31:32 -0700 (PDT)
From: terry michael <OEA51@go*.co*>
Subject: Re: Redundant Rebreathers & The Doux de Coly
To: isler <isleroc@sp*.ch*>, "techdiver@aq*.co*" <techdiver@aq*.co*>,
     "" ,
OK, I'll inform my eight year old son that it was your idea and not his, thanks.

-----Original Message-----
From: "isler"<isleroc@sp*.ch*>
To: "techdiver@aq*.co*"<>,
Date: Mon Oct 08 12:34:41 PDT 2001
Subject: Redundant Rebreathers & The Doux de Coly

>Hi everybody,
>I am new on the list. I am interested in  diving with rebreathers. I
>speak French so, my sincere apologies for my approximativ English.
>I red the website of Reinhard BUCHALY and Michael WALDBRENNER, and I
>would like to precise some points in this following message. The
>translation is good, because I gave it to a good Friend much better than
>me for Shakespeare language...
>Some informations about the exploration of the Doux de Coly.
>Since 1984 the Doux de Coly is the longest known sump in Europe.
>Summary of explorations.
>1972. PJ DEBRAS reaches 352 m (a remarkable performance at that time).
>1981. Both Claude MAGNIN & Olivier ISLER dive one after the other and
>MAGNIN stops at 1750 m.
>1984. MAGNIN reaches 2630 m, and ISLER stops at 3100 m (up to this time
>all dives are made with open circuits).
>1991. ISLER stops at 4055 m using the RI 2000 (redundant rebreather with
>3 independant circuits).
>1998. ISLER progresses another 250 m (to 4300 m) having unrolled 1150 m
>of guide-line, again using the RI 2000 rebreather.
>2001. Reinhard BUCHALY and Michael WALDBRENNER reach a distance of 5000
>At first, congratulations to Reinhard and Michael for their remarkable
>dive. The Doux de Coly carries on and it is not the end. I am very happy
>to see that my difficult dive in 1998, where I found the continuation of
>the cave, has so successful consequences.
>The dive of Reinhard and Michael is reported with a lot of details on
>the attractive website www.tekdyk/doux.
>Unfortunately, an error appears at the "Welcome" page of the site. The
>assertion that  "... all dives were directed using the DIR philosophy
>developped by the floridian cave diving team WKPP..." is NOT correct. In
>fact, the dive was directed using an intermediate philosophy between
>that of DIR and the rebreather redundancy developped by myself (as
>mentioned on the site).
>The analysis of their dive in fact shows that they both carried 2 X 20 l
>tanks on their back (return on open circuit in case of rebreather
>failure). They dived as 2 divers together, as in DIR philosophy. Beyond
>a distance of 800 m, no safety or relay cylinders were placed in the
>sump. The reason was that both divers used the double rebreather RB 80.
>This is undeniably my philosophy of using Redundant Rebreathers.
>It looks evident that rebreather's redundancy, nevertheless thrown back
>by the WKPP, was decisive in their successful dive. If they had followed
>exact DIR philosophy, Reinhard and Michael both would have used a single
>rebreather, and they would have relied on safety cylinders staged far
>down into the sump (maybe 3000 m or more), impossible to carry out
>without a powerful support team.
>As for myself, I am proud to note that, after 11 years of existence, my
>philosophy of Rebreather Redundancy, has begun  at least to appear in
>extreme diving activity. Even if it is not yet fully accepted, the idea
>of Rebreather redundancy goes on, in Europe with Reinhard and Michael
>and in Australia with David APPERLEY.
>I will end with a note that if Reinhard and Michael plan in the future
>to cross the stage of total Rebreather Redundancy (by using an
>additional small front mounted safety rebreather) they will both have
>quadrupled redundancy, when, during my own solo dives, I had at my
>disposal triple redundancy. With such a configuration, the crash risk
>becomes tiny.
>Olivier ISLER

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