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From: <bdi@bd*.co*.au*>
Date: Sat, 06 May 2000 17:34:30 +1000
To: techdiver@aquanaut.com
Subject: Re: advise for new tekkie
At 09:59  5/05/00 , Ee Michael wrote:
>hi there,
>have a few qus that i would like to clarify on equipemt and the DIR
configuration with the more expereinced ones out there...
>
>1) what is the recommanded lift of a  bladder ? i'm from singapore and
currently studiyng in australia...a tek course of cos means we need our own
equipemnt so i was thinkning of a wing bladder. what is the recommanded lift ?
45 pounds ,65 pounds or 100 pounds ?

55 lbs


>2) IATND recommanded a 22.5 kg lift bag,  i have a 25 kg lift bag already and
if i go into tek diving , i think i'd go into only the noromixc with tehnical
wreak  level.This means i 'd have max of a double 13 or 15 and 2 stage tanks (
maybe 1 for travel mix ., the other for deco ) , is a 25 kg lift bag sufficient
in our waters ?

You would properly be diving with manifolded al 80s.
and alloy stages. The 25Kg lift bag is ample.


>3) from australia and around asia , the maximum we ever need is a semi-dry
suit. 

Wrong. In most of Australia, if you dive deep and do 
decompression dives, you will get chilled in a wetsuit. 
We dive dry. 

>Thus the ques of redundencay comes in ,do we OR do we NOT need a double
baldder ? the issue of it being a failure point does not make sense to me as we
can just connect one inflator at a time rite ?

You do NOT need a double bladder. If you dive a 
wetsuit you should be using aluminium 80s manifolded 
together. And alloy slings.


>4) for the convetional backaplte, if we use singles , we need a singel tank
adaptor..but how bad is the drag ?

Of the adaptor? Undetectable.

>5) for wings floation, it is known that it has a prolemn enabling a diver to
maitain a vertical postion while on surface

Wrong - who's teaching you this crap?

>...are weights necessary on the tank cam bands to help bring the diver into a
vertical postion ?

No.

>6) bungees or without bungees on bladder ? why ?  the DIR manner said that the
bungees prevents the hose from inflating properly but this means that the diver
have tied them too tight  !!! so bungees or without bungees ? we can always
losen the bungee right ?
>aslo i have tried infltating an OMS baldder with bungee orally and there is no
problem with it !!

Michael what do you really want? Advice from experts
or the opportunity to defend a piece of crap?

You ask about the drag from a tank adaptor but are 
prepared to ignore it when it comes to bungy wings. 
What gives? Made up your mind already? There's no 
comfort for you here, then.

>7) wings flotation have the problem of tank wrapping when we use singles or
very small doubles 

Why would you ever use very small doubles? Get real.

>..is this issue exaggerated or serious ? can we use the bungee to reduce this
effect ?

This issue is very serious. It means you don't have enough
sense to use a smaller wing with a single tank.

>8) i feel that the Harothigan method is very comprehenisve but i've been
thinkning on the issue of the bungees. with bungees ,
>a)the bladder is at a miuimin size
>b) one can re-adjust the air in the bladder to compenste for stages
>c) minimises wing wrapping
>
>
>cooments and advise please

Michael, sit down, shut up and listen.

Bungee wings exert drag when you're swimming. If the bungees are 
loose enough not to restrict oral inflation at depth they are 
not tight enough to do what OMS claims they do and are 
therefore totally unecessary. WHen you do inflate them, 
they constrict the bag before full bouyancy is achieved and 
then blow off the OP valve. Because they're crinkled up they
trap gas and are hard to fully deflate - which can be a bitch
on deco. They piut the bouyancy beneath the tanks, rather
than around them. Not stable. If you finally get rid of the bungy, 
you'll find that the bladder is too wide behind the neck and your 
bouyancy is never right. The bungee wings are also implicated in 
training deaths.

Flat wings - halcyon or diverite, sit flat against the 
tanks and wrap up round them at the outer edges - as low profile 
and streamlined as you can get.


Who told you about the bugy wings being OK? The same person
who maintains wings "has a prolemn enabling a diver to 
maitain a vertical postion while on surface." Who's telling you
this stuff?

If you're in Sydney give me a call on 02 9977 0307. I have some
time free next week and can show you why the DIR rig works and 
the bungeees don't. You'll have to cough up the name of your 
instructor though.

rgds billyw



>thanks
>mike
>
>ps : guide me according to the qus asked ok...easier for me to undersatnd !!!
>
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