On Thu, 26 Aug 1999 07:41:19 -0400 (Eastern Daylight Time), Art
Greenberg wrote:

>On Wed, 25 Aug 1999, Sean T. Stevenson wrote:
>
>> There is more to a successful technical diving venture than just
>> competent divers.  Effective planning and competent surface support
>> personnel are mandatory.  The lift bag is not intended to be chased
>> down by a ship, but rather by the (mandatory) chase boat, while the
>> primary vessel remains at anchor.  A competent boat crew comes in handy
>> here.
>
>Sean - chase boats are very, very rare here. I can't claim to be "boat
>wordly", but none of the boats I've used have them. That might not be an
>optimal situation, but it is the way things are. I can't afford my own
>boat, so I dive the way I must to accommodate the way the boat Captains
>run their operation.

This sounds like the crux of the problem.  Here on the British Columbia
coast, most of the boats I dive from are reasonably large and have a
tender or RIB of some sort for picking up divers.  I suspect that if
enough requests were made of the charter operator to utilize a chase
boat of some sort, that they could accomodate you.

>
>> For some reason, NY/NJ divers seem to feel more comfortable when
>> they're tied to something.
>
>No. It's not for comfort. It is MANDATED by the boat operations. Protocol
>for a pulled hook is that the boat will keep station near the wreck, but
>far enough off to avoid making chum of ascending divers. When all of the
>divers are on the surface, the boat will then move in to pick them up.
>Simple and effective.

Exactly why you should have a chase boat.  What are the typical current
conditions during dives there?  Enough to carry a decompressing diver
well out of visual range of a mobile chase boat unless he ties himself
to the wreck?  If the current is that bad, would not the upline assume
a horizontal orientation, with the net result that you have a diver
struggling to hold on to the spool in a heavy current while trying to
maintain his stop depth and achieve an effective decompression under
duress?  Does anyone else think this makes sense?  A drifting deco puts
the diver at minimum exhertion.

>
>> As Jim mentioned, the biodegradeable sisal line that is typically
>> employed on the Jersey uplines has a tendency to become weak and fail
>> at the worst possible time - in an emergency.  Braided nylon line or
>> equivalent is a better choice.  If 1/16 is unsuitable for the
>> environment, such as in wrecks, then use larger or more durable line -
>> just put it on a well designed reel instead of the Jersey spool.
>
>I use 1/8 inch braided nylon for my upline. Its strong enough to take a
>lift bag and a couple of divers. It is, however, too big to put on a wreck
>reel. My upline spool is no larger than an LP argon bottle. It is out of
>the way, on the right hand cylinder, and easily accessible.

Try a larger reel.  I have stowed large items on a rear d-ring on the
crotch strap beneath my tanks with no problem.  The problem with R/H
cylinder stowage is that if you need to reach behind you for any
reason, you can't get around it without removing it first.  You can
reach around a canister light on the right hip, or an argon bottle on
the left, but not both.  Also it adds unnecessary drag which is not
true of the rear d-ring position.

>
>> One tool for two functions - starting to make sense?
>
>No. I use cave line for my guideline. Its too small for an upline. It
>would be less than optimal to have deployed the bag for an ascent only to
>have the line break.

Not advocating using cave line, just a different stowage device.  You
can get high capacity reels, you know.

>
>> The reel also allows deployment with one hand only, leaving one hand
>> free to deal with emergencies.
>
>I have a team mate with me to help deal with emergencies during the 1-2
>minutes it takes to get the bag to the surface and secured.
>
>> It stows easily and cleanly, and is deployable in seconds.
>
>True of the little spool I use, too.
>
>-- 
>Art Greenberg
>artg@ec*.ne*

-Sean






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