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Steve,

n a message dated 98-01-10 00:50:38 EST, you write:

<< I agree with the three man team as being the best option but not
always 
 attainable.
 
 where do you stand on the surface support issue is it neccesary or not?  
 I think that it may assist the dive but is not a necessity as long as 
 the ice is anchord a continuous line to the entrace is maintained, 
 proper gas management is observed and extreme depth is avoided(generally 
 most of the lakes we dive do not exceed 100feet so this is not an issue)
 
 SAFE DIVING 
 
 STEVE >>


---------------------------------------------------------
   What you have said here is that a support crew is not a necessity as long
as everything goes as you hope it will.   Well, you're absolutely right !   

I know you did not mean it this way, so ;

    I see your point in questioning the need for the big support crew in light
of the fact that other overhead excursions, specifically cave, do well without
them.   The only meaningful difference I can see in the two environments is
the fact that the exit can become plugged and poses a hazard to other users of
the waterway.

    If these frozen lake environments were actually huge rock rooms with a
single hole in the top would we dive them any differently than caves (other
than having someone to keep the hole clear in some cases and lights) ? 

    It could be said that any support is a luxury and it could be said that
any need for support is a handicap.   Support can make the work of diving
easier, improve the potential outcome of an emergency, and benifit the effort
with a broader range of experience and/or expertise , but it is never actually
necessary, so all judgments as to it's need will be subjective or qualified by
various factors.

   I tend to think like Bob Sherwood that a single highly reliable line for
the divers is a more reasonable setup than individual teathers for experienced
divers staying together.   (this from a strictly accademic viewpoint, not
personal experience with ice diving)

    I see the dry surface crew's primary function as maintaining the itegrety
of the exit point and, as a side benifit, helping on the surface with a
disabled diver and emergency procedures.   
    There is a chance of a disabled diver slipping under the ice and drifting
away while attempting to get him out of the hole; a possible justification for
having a line on each diver or for a support diver considering that there may
be no one in the water to retrieve him if his partner is lost or also
disabled.   So the teather and the support diver effectively extends the reach
of the surface crew who otherwise would be unable to do anything at all for
the divers unless they are in the hole.   

    I don't see any inherent danger or problem with running a single reel of
tough line between two "experienced" ice divers as long as technique gards
against the danger of droping the reel and as long as you can feel the line
but I can see too many lines presenting a greater risk than bennifit for any
group of divers, especially those of lesser experience or expertise.    
     
    I don't see any inherent danger in diving without a support crew as long
as the integrety of the anchor point and exit hole is insured.    It seems
that you have the block of ice under reasonable control but I might make a
second anchor point near the hole but under the ice for my guide line to gaurd
against tampering by ice fishermen and kids or the chance of some piece of
wreckage blowing across the surface of the lake and disloging your spike.
    
    This is all a matter of risk control and acceptance but both the risk of
the dive itself and the risk of not being able to handle an emergency
effectively must be considered.   I can see an inherent increase in the risk
of not being able to handle an emergency as effectively as is reasonably
possible without a support crew, which poses some legal problems and ethical
responsibilities for leaders taking others diving .    
    Can you get your buddy out of the hole alone if his drysuit is flooded
and/or he is unconscious?   How much time will you loose by having to doff
equipment before you can work effectively?   Is the fact that there will be no
one to send for help in such a case acceptable to both you and your partner ?
     

Anthony and David,

You wrote,

>Chuck, three of the five are up on the surface where they can talk to
>each other; only two are in the water.  Rope pull signals are used for
>divers and tenders to communicate.

Thanks,   
Obviously, I was thinking like a cave diver, as you say, where the whole
"team" is in the water and thinking of the support crew as a seperate entity. 

Chuck Boone
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