On Wed, 17 May 2000 23:53:56 EDT, IHOPPOET@ao*.co* wrote:

>In a message dated 5/17/00 8:27:31 PM Central Daylight Time, 
>ststev@un*.co* writes:
>
><< Jason, this is ridiculous.  If you are diving with a pony bottle,
> either you are diving with unnecessary redundancy, at the expense of an
> increased risk of entanglement, or if you actually need it, are diving
> with a level of redundancy inferior to that provided by the isolation
> manifold. >>
>
>Let me set a scene for you. You are a back up diver, and your primary diver 
>give you a rope signal, he needs help. You go down, he gives you the hand 
>signal, not only is he caught up, but he is hurt, and here it the kicker, he 
>is about out of air.  BTW this is black water. What do you do? 

First off, the scenario you describe should only come about if the dive
is poorly managed.  You should know the gas consumption rates
(estimated) for each diver, and try to get the diver back on deck with
2000 psi.  That aside, if the diver has been allowed down long enough
that he could conceivably be out of gas, the standby takes an extra
bottle.  If there has been a large rush of bubbles from the diver's
location indicating a freeflow or serious hyperventilation, the standby
takes an extra bottle.  If the call for assistance is not a 2-2-2 but
rather a panic signal, the standby takes the extra gas.

>Do you give him your octo? If yes then what? You can't cut him out.  do you 
>go back up get another tank with a reg on it, come back down and give it to 
>him, hoping he is still alive? Or do you give him your pony, which slips 
>right off your set up, go back up get another 80 and then work on cutting him 
>out? I answer yes to the last option. 

As a standby diver, under no circumstances do you make contact with the
distressed primary and then leave him !  In this scenario, the events
leading up to the primary diver's call for assistance would prompt me
to have the standby take additional gas on his first response.  This
means a full size tank so you do not make two trips.    Anticipating
the divers requirement for extra gas is paramount, and permits you to
free the entangled primary while maintaining physical contact.  I don't
know if you do swiftwater dives, but if so you will realize just how
important this contact is for alleviating fear.

>
>As far as unnecessary redundancy, I don't really believe in those two words. 
>for example, I dive with 3 pairs of shears, and a knife. A pony as you well 
>know, and when I am the primary diver, I have a back up diver ready to come 
>down, and a 90% diver, 90% ready to come down in case something happens to my 
>back up. 

Primary, secondary and 90% tertiary is SOP.  I try to keep as
streamlined as possible, which means DIR, except that you need to carry
the necessary tools, and use the full face mask if you require hardwire
comms, or if the water is contaminated.  Tools include 1 knife, 1 pair
of shears and 1 pair wire cutters in a low profile sheath on the waist.
 As far as unnecessary redundancy, you need to consider the benefit of
carrying the  pony versus the risk of entanglement.  If you track the
divers and manage your gas properly, this is never an issue.  Then,
redundancy in the form of an additional air source is only necessitated
in overheads (structures, capsized vessels, etc.) or in water
approaching freezing, in which a first stage failure is likely, and you
need isolation manifolded twins for the component failure
survivability, as opposed to the gas capacity.  In this case, the
backup would just donate the long hose if necessary.

>But hey everyone does things a little different. 
>
>Thank you
>Jason Miller
>NE Oklahoma
>USARU

PSD and DIR are not mutually exclusive.

-Sean


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