Mailing List Archive

Mailing List: techdiver

Message Display

Question:

 The use of an isolator valve on doubles is, as far as I understand at
my admittedly novice level of cave diving, required as a part of the DIR
system, which I am embracing more and more as I dive it, read it and
think it. I know that no "buts..." are allowed in DIR. but... 

In an overhead environment the diver seeks, I believe, to minimize the
degree that his manifold, regs, hoses, etc. might impact on the
overhead, and as a consequence, fail. I have been told that this is one
reason, among many, to eschew the use of regulators with yokes in favor
of the DIN type, since the latter have a much reduced profile. 

In the Yucatan, where I received my training, a very experienced cave
diver whose name would be easily recognized by many on this list, told
me that his personal choice of manifold excluded the use of isolator
valves because of his experience and concern that the protruding
isolator valve would and could accidentally strike the overhead and
fail, very likely resulting in a catastrophic loss of gas. His
experience in the course of many years in the cave diving business: "of
6 near misses (involving manifold failure), 5 involved isolator valves." 

Since I am still in the formative stages of my understandings of the
best and safest (read DIR) cave diving techniques, this has caused me a
bit of cognitive dissonance that can not be dispelled with dogma, only
logic, since I am as of yet not a total "true believer". 

Curt Degler

further...

This mail list, more than all the others I participant in,
harbors some real pearls! Did anyone miss this exchange:

Karen Nakamura writes:

>George -
>Thanks as ever for the polite response.

and George Irvine responds:

> ...this Nagasaki chick...

	and

>An idiot is an idiot...and that always comes out in the attitude which
>they can not hide.
--
Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'.
Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.

Navigate by Author: [Previous] [Next] [Author Search Index]
Navigate by Subject: [Previous] [Next] [Subject Search Index]

[Send Reply] [Send Message with New Topic]

[Search Selection] [Mailing List Home] [Home]