Well I'm glad to see this discussion has remained relatively benign ;-)
I agree with you Tom in one respect, and that would be trying to expose the
student to as much as possible to give them a good knowledge base.
This would definitely be a bad situation, but I agree with Jess on his
judgement and configuration points. I would have to point out that if a
restriction was so nasty that air sharing is impossible, then even a top
notch diver would not likely make it through in time and then wait for the
donor to make it through also. A restriction that bad could kill the OOA,
hence blocking the exit for the donor. Even if the donor went first, I just
don't see enough time if the restriction is that bad.
Judgement is the key word here. Sidemount is unique in that you have two gas
supplies, therefore leaving you with at least one for this scenario. This
takes the place of the "donor" in this situation. When sidemounting, I will
never remove a bottle to negotiate a restriction (on penetration), this
keeps me from ever having to go through something (on exit) with anything
less(at least one bottle) than my own gas supply. I will never "no mount",
which has redundant regs, but no provision for a catastrophic air loss, i.e.
tank neck o-ring failure. While this is being done, it won't be done by me.
I have been in many river caves (sidemount) in the Withlacochee that one way
travel is the only thing possible. I have backed out more than 100 feet in
vis so bad that it was almost  mud. I turned my light out because total
blackness was more comfortable than actually seeing what I was in. This took
an incredible amount of time to do and  requires mind control that I didn't
know I had. I will NEVER put myself in that kind of situation again.
My vote would be enforce the notion that no restriction should be pushed (on
penetration) that can't be negotiated with either air sharing or a REDUNDANT
gas supply on the diver. Some no mounters may object to this but that rig is
essentially a single tank cavern diver taking his stuff off and pushing it
through a restriction.
There are some places that humans just don't belong.
Good judgement will prevent the scenario altogether.
Dell Motes
Dive Rite
117 W.Washington St.
Lake City, Fla. 32055
www.Dive-Rite.com




-----Original Message-----
From: Jesse Armantrout <armantrout@wo*.at*.ne*>
To: Tom Mount <TOM.MOUNT@wo*.at*.ne*>; Richard Pyle
<deepreef@bi*.or*>; kirvine@sa*.ne* <kirvine@sa*.ne*>
Cc: cavers@ca*.co* <cavers@ca*.co*>; Randylabel@ao*.co*
<Randylabel@ao*.co*>; rebreather@nw*.co* <rebreather@nw*.co*>;
techdiver@aquanaut.com <techdiver@aquanaut.com>
Date: Tuesday, November 10, 1998 3:51 PM
Subject: Re: gas sharing and restrictions in caves


>This sounds like a dubious solution to an improbable scenario when what
>should have been addressed were fundamental problems.
>
>Judgement:  You must know when not to push a bad situation.  If you have
>the wrong gear or amount of gas, don't go through the restriction.
>
>Gear configuaration:  This describes a scenario that should only be
>encountered when side mounting, otherwise,  bad judgement has been shown.
>
>Gas Management: While the rule of thirds is better than no rule at all, the
>rule of coming out with 2k on your back is much better and is what needs to
>be taught.  Take stages if you need more gas.  Place safties before and/or
>after restictions.
>
>Too much valuable class time appears to be being wasted on "what if's" that
>could be eliminated with proper basics.
>
>Jess
>
>
>----------
>> From: Tom Mount <TOM.MOUNT@wo*.at*.ne*>
>> To: Richard Pyle <deepreef@bi*.or*>; kirvine@sa*.ne*
>> Cc: cavers@ca*.co*; Randylabel@ao*.co*; rebreather@nw*.co*;
>techdiver@aquanaut.com
>> Subject: gas sharing and restrictions in caves
>> Date: Tuesday, November 10, 1998 11:11 AM
>>
>> George
>> First under all circumstances possible divers are to remain intact
>sharing
>> gas, through restrictions etc. In fact when I and I imagine other cave
>> instructors teach gas sharing we have students share gas through
>> restrictions. One of my favorites is the half hitch in Madison. Another
>one
>> is the restriction in the Gonzalla room tunnel and a third is the
>> restriction coming out of devils eye. In all these normal gas sharing is
>> performed right through the restrictions I usually do a few restriceion
>gas
>> sharing drills with the divers sharing gas at all times.
>>
>>
>> SECOND IN THE EVENT THERE IS SUCH A MAJOR And Complex RESTRICTION
>> ENCOUNTERED THAT THE DIVERS CANNOT GET THROUGH IT WHILE SHARING GAS, a
>> situation exist that they must separate in order to get to a point where
>it
>> is possible to share gas again, the procedure of having the donor allow
>the
>> out of air diver to get several deep slow breaths and become as calm as
>> possible before the temporary interruption of the act of gas sharing due
>to
>> the nature of the MAJOR restriction (remember this is a worse case
>scenario
>> not the average restriction, this is a very major restriction event,
>making
>> it virtually impossible to continue sharing gas and still be able to exit
>> the cave.) it was felt that if one diver had to lead through such a
>> restriction the donor should, as the out of air diver could relax and see
>> that the air supply was infront of him/her not behind,
>> The donor will at the earliest point where it is possible to get the
>second
>> stage /long hose to the diver signals the out of air diver to come and
>get
>> the gas the diver then swims towards the air supply and gets it.
>>
>> Hopefully most divers will not be in areas that have such major complex
>> restrictions, but the process was developed so that there would be a
>> predetermined plan of action on how to handle such a drastic situation
>> should it occur. The other choice would be that in such a situation the
>> diver out of air goes first which means he begins to exert, then exit the
>> restriction and have to turn facing back into the restriction to get air,
>> that is more difficult and stressful than the first option.
>>
>> A third approach of course is do not teach anything for this worse case
>> scenario and if it happens to a dive team let them figure it out on their
>> own, under stress without having the benefit of a dry rehearsal or
>thoughts
>> as to how to address such a possibility.
>>
>> What prompted the development of this drill was from early blue hole
>> explorations where we did have restrictions that made it virtually
>> impossible to share gas through so this drill was introduced for a worse
>> case scenario, not a routine gas sharing exercise for all restrictions.
>>
>> Now for those of you who mistakenly assumed that this was a procedure for
>> any restriction hopefully you now know better. Maybe you would like to
>> comment then on
>> 1. Should this remote what if situation be taught
>> 2. Should this type situation not be addressed and just let the divers
>who
>> may face this situation someday figure it out under a real situation
>instead
>> of a simple training exercise for a worse case scenario, which is how it
>is
>> descried. And practiced.
>>
>> To summarize all students are taught to remain actively sharing gas (in
>an
>> out of air situation) under any condition where it is possible to do so.
>> They are then exposed to a worse case scenario where a restriction is so
>> major and complex that it is impossible to go through it in a gas sharing
>> mode thus this is a alternative that will work.  Students are also taught
>if
>> possible that gas sharing should start with a little gas left in the
>> cylinders in event of such a situation, but again the most serious
>situation
>> we can imagine must also be at least introduced to the student.
>>
>>
>>
>> Respectfully yours,
>> Tom Mount
>> CEO IANTD World HQ
>> http://www.iantd.com
>>
>> -----Original Message-----
>> From: Richard Pyle <deepreef@bi*.or*>
>> To: kirvine@sa*.ne* <kirvine@sa*.ne*>
>> Cc: cavers@ca*.co* <cavers@ca*.co*>; Randylabel@ao*.co*
>> <Randylabel@ao*.co*>; rebreather@nw*.co* <rebreather@nw*.co*>
>> Date: Tuesday, November 10, 1998 8:12 AM
>>
>> >
>> >
>> >
>

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