Conference noted::scuba

    I had entered a long detailed reply, but the notes editor doesn't
    have a recovery log and the network connection went down so I lost
    it.  Here's the very short version.
    
    What type of diving do you want to do?
    What are your needs and resources?
    
    Basic differences are gas volume, weight, cost, and compatibility
    with other tanks.
    
    Rob

    What type of diving do you want to do?
    What are your needs and resources?

    I want to do wreck diving.

    I know the costs/gas volumes/etc.  I have heard that with HP tanks you
    frequently won't get a complete fill (since you can't overfill 10%), that
    the higher 3500 pressure wears regulators significantly faster.  On the
    other hand, HP is smaller and lighter for the same gas volume.

    Dave

    
    >>> I want to do wreck diving.
    
    Do you mean recreational wreck diving, i.e. no staged decompression
    diving or extended range/tech wreck diving?
    
    >>> complete fill... regulator wear...
    
    It is true that many fill stations will not fill HP tanks to 3500
    much less 10% over.  If you have good equipment and have it annually
    serviced the high pressure wear should not be a problem, partially
    because it is only in the high pressure area for a few minutes until
    you breath off some of the pressure.
    
    I have been diving with pressures starting from 3400 to 3800 psi
    for 3 years and I have not had any equipment problems.
    
    Another concern may be the availability of a fill station that will
    overfill LP tanks.  Many tech-divers regularly get 50% overfills.
    
    Rob

      <<< Note 1398.3 by TAPE::SENEKER "Head banging causes brain mush" >>>
                  -< getting 3500 psi fill may be a problem >-

    
>    Do you mean recreational wreck diving, i.e. no staged decompression
>    diving or extended range/tech wreck diving?
    
    I am doing the former at the moment; will also do the latter if possible
    at reasonable cost -- or I win the lottery (and I find others to get
    involved with); Based on current info I would expect to get a closed
    circuit rebreather if I were to be heavily involved with staged
    decompression diving;  I have a Zeagle Tech 50D reg /w cold water kit
    (soon to have two) and going from single alu 80 to independent 80
    doubles to single, then independant doubles/then probably manifold doubles
    of whatever HP or LP tanks I get.

    Also have a Beauchat (Cochrin) Maestro Pro EAN computer, which handles
    switchover between two mixes, #1 EAN 21-50, and #2 up to 100%
    Oxygen (21 to 100%), and a drysuit, and will probably want to get
    Abyss deco software before I got much into deco stops.

>    It is true that many fill stations will not fill HP tanks to 3500
>    much less 10% over.  If you have good equipment and have it annually
>    serviced the high pressure wear should not be a problem, partially
>    because it is only in the high pressure area for a few minutes until
>    you breath off some of the pressure.
>
>    I have been diving with pressures starting from 3400 to 3800 psi
>    for 3 years and I have not had any equipment problems.
>    
>    Another concern may be the availability of a fill station that will
>    overfill LP tanks.  Many tech-divers regularly get 50% overfills.
    
 
     So it sounds like you have a shop (or shops) that will give you a good
     fill to 3500 or beyond on HP tanks.  Are you implying that tech divers
     are using their own compressors to overfill up to 50%?

>   I am doing the former at the moment; will also do the latter if possible
>   at reasonable cost -- or I win the lottery (and I find others to get
>   involved with);
    
    Tech diving is much more expensive than recreational diving.  The
    biggest reason for this is the cost of providing yourself with enough
    equipment (and experience using it) so you have wider margins for
    error while diving.  Wider margins for error increase your chance of
    returning from the dive in good health.
    
>   Based on current info I would expect to get a closed circuit rebreather
>   if I were to be heavily involved with staged decompression diving;
    
    Yes, this would work but a fully redundant CCR is the most expense
    means to currently go tech-diving.
    
>   I have a Zeagle Tech 50D...

    I am unfamilar with Zeagle regulators so I cannot make any comments.
    I have gained my comfort level with my equipment via my time of use
    with no problems and the time of use of others I dive with that have
    had no problems.  One of the hardest things about tech-diving is to
    open your mind to new ideas, realize your personal limitation, and
    start taking actions to improve yourself.  Another big problem is
    that you have to address the issue of dying while diving.

>   on overfills...

    Many tech divers are dive store owners.  Also, due to the nature of
    tech diving tech divers/tech dive store owners don't mind pushing
    the envolope.  So if the dive store owner overfills for themselves
    usually the will overfill for you, once they know you are a tech-diver
    (some may require that you are a regular customer).

    I guess to answer your question ...using their own compressors....
    the answer is:	Yes, in the more serious tech divers.

    Also, on your growth path for tanks, I recommend that you go with
    alu 80's because they are inexpensive and if you really enjoy tech-
    diving you can change them from your primary backmount tanks to stage
    tanks, deco tanks, etc.  Also, if you don't like tech-diving you will
    have some good recreational diving tanks.

    Rob

	Is it fair to say (on the original subject) that HP tanks are
	preferable to LP if your shop can fill to 3500, you inspect
	your reg regularly, and you don't have the 50% overfill
	option?
	
	Dave

    Yes, I would agree that is a good combination.
    
    Rob