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The problem with military trainers who are now civilians and who have only recently begun to do deep diving like my friend Leon Scamahorn is they don't have a clue how to dive in the real world of deep diving because they never did any at all or only a little in the military. I know, ask them and they will tell you that they have hundreds of hours of deep diving experience. Ask them where and when. Leon knows rebreathers, Leon does not know deep sport diving. He can learn. For example, the buddy hose on a rebreather mentioned in Kevin's post is useful ONLY if each buddy has practiced tandem breathing extensively, as Leon will tell you. It is not like open circuit scuba where two divers can breath one first stage simultaneously. With a rebreather you cannot both be sucking in at the same time or you will be sucking wind. Leon needs to get with the program and start learning proper bailout procedures for deep open water diving for civilians so he can teach the same to civilians- which he says he will do- and, in fact, is doing. We don't need the "one-rope" technique (as applied to rock climbing) in deep civilian diving, we need the boy scout approach- be prepared. If you don't see the difference, then don't buy a BioMarine rebreather, buy another brand so you can die using it instead. About the Rebreather Forum: Another thing that came out at the rebreather forum is that rebreathers WILL replace open circuit scuba as the means of sport diving. Within a few years, only the truly stupid will be using open circuit for anything. Since the high cost of rebreathers will mean that a large portion of divers will not be able to afford to own a unit and will- by necessity- have to give up the sport, then lists like Techdiver and Scuba Forum will be pared down to only the truly enlightened- getting rid of most of the bullshit we see on here- and ex-divers will form their own Basket Weaving lists and Science-Diving-in-the Lab lists. Simulated Diving software will become really big so ex-divers and wannabe-divers can talk about transient O2 spikes like it actually had any meaning in the real world of diving. And, finally, short male ex-technical divers can get erect looking wistfully at their generic Rebreather Instructor cards while nailing the mouthpiece of their old OC second stages. On Tue, 1 Oct 1996, Richard Pyle wrote: > > > You bring up a good question of redundancy that has been addressed before on > > this forum - how much is enough? > > > > EX: Your rebreather craps out totally: > > > > --> You gotta go to your open circuit bailout. > > a) How much gas do you carry? Some folks say "enough to complete your deco" > > which makes total sense. Others say "Just enough to bail." Some, like > > Leon, actually advocate and teach NO open circuit bailout - total reliance on > > the unit. > > > > But say you've decided to carry enough open circuit gas to do your deco up to > > 20 ft. where you've got your O2 hung. Now - do you carry ONE second stage > > reg, or TWO, in case one craps out? > > Did you see my presentation at the forum? I carry 80 cf of diluent - > usually 30 cf heliox and 50 cf air - which sure as hell isn't enough to > get me all the way to my 20 ft stop on a lot of my profiles. The idea is > that it is enough to buy me some time to get out of deep water, alert > surface support that I need more gas, and allow time for surface support > to get that gas down to me. As for the question of 2nd stages, the Mk4 > does not run the integrated OC bailout supply through the rebreather gas > manifold, which means I have the option of plumbing in a secon gas block > (generally a real fustercluck), or having independent 2nd stages on each > of the offboards. I have been opting for the latter. The Mk5 will route > the integrated OC 2nd stage via the rebreather gas manifold, which means > active diluent is always equal to active OC supply (i.e., I can access all > onboards, as well as all offboards via quick disconnect, via the > integrated OC 2nd stage). Consequently, my philosophy about FFM's may > yet change. Nevertheless, I'd still like to maintain my ability to > conduct a spirited debate with Allah, if & when he calls my name (when > the loop crashes and the integrated 2nd stage goes boom), so I'll > probably "T" - off an backup second stage to the Mk5. > > > If you advocate TWO - then what happens if your first stage blows (which I > > have seen happen)? Do you carry a second bottle? If you do, do you use ONE > > second stage or TWO? > > Five bottles (Transportable Pressure Recepticals), five 1st stages, 2 2nd > stages would be my preferred configuration. Five TPR's are 30cf Heliox, > 30 cf air, 20 cf air, and 2 x 13.5 cf O2. > > > See where I'm going? Redundancy can be carried to an extreme level. For > > total safety, you could carry 2 bailout bottles with 2 regulators each. Then > > you'd have a total of 5 regs down there (actually 4, but lets pretend your > > mouthpiece is a reg for the moment). This gets even more complex if you > > decide to carry bottom mix, and travel mix. Shee-utt. Now you look like me > > in one of those stories I write... > > The goal is to maximize probability of staying alive & healthy while > accomplishing the mission, and minimizing the probabiliy of a need to > prematurely abort the dive. There is a point where excessive redundancy > starts reducing your probability of staying alive and healthy, and > certainly starts reducing your ability to accomplish the mission. > > > When it comes to rebreather bailout, the coolest thing I saw was the "Y" hose > > connectors that Leon had for his CCR-1000. It allowed a second set of hoses > > and mouthpiece to be worn on the back of the unit. If your unit took a dump, > > you would swim over to your buddy (which is required in this particular > > scenario), and latch on to his back like an abalone, and start breathing > > through that spare pair of hoses, through his breathing loop. Leon states > > unequivocally that the CCR-1000 can keep two divers alive this way. I have > > no idea if that is completely true, but if so, that's the ultimate "buddy" > > system. > > Sounds like an excellent solution. > > > As you know, I'm still new to this rebreather game, but I can see that it is > > easy to start sliding down the slope of multiple redundant systems to the > > point where you are wearing so much gear its impossible to swim, or that the > > logistics of hanging bottles is so complex as to make each dive a major > > production. > > That's why you gotta find the ratio that works best for you. The system > I outlined above for me (5 bottles, 80 cf diluent) is for dives in excess > of about 280 feet. Shallower dives, and dives of shorter duration, may > or may not require less. > > > I know there is a compromise somewhere in here, but I haven't quite found it > > yet. > > I don't think any of us have yet. > > > BTW, Rich, you missed a great BBQ at my house. Dick King, Rod, John, Pete > > Heseltine, Leon Scamahorn, and another fellow whose name escapes me (sorry) > > came over, talked rebreathers, ignored the two young women there, ate BBQ > > chicken like it was going out of style - drank beer, and walked out the door, > > still debating the merits of some rebreather part. All in all, a great > > evening. > > When was that? I went to the Hruska & Lesser deal, which was both free & > excellent. > > Rich > -- > Send mail for the `techdiver' mailing list to `techdiver@terra.net'. > Send subscription/archive requests to `techdiver-request@terra.net'. >
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