jonnythan:
That's a lot of talk for justifying the brilliance of equating steel bolts and plastic buckles.
Heh.
-hh:
...despite what you claim, I see that you're slowly coming around to the realization.
...Realization of what? That everything's a failure point?
It's not a "slowly" anything - I've known this all my life.
But practically speaking, you can't refuse to drive to work because the stoplight might accidentally shine green on both sides, causing massive car crashes all over the place.
...The factor of "likelihood" must be factored in... And at some point, you have to stop considering that a meteorite might fall on you, and that it's okay to go outside.
...What point is that in scuba diving? Well, I believe it practical to learn how to don and doff your rig properly, so that it can be done in any condition. If that takes a QD, then so be it... But I would suggest that other methods be learned, so that you're not relying on a piece of plastic which can break (with a frequency, I'm seeing, of about 1 in 250), jam, become something that can't be operated with gloves or cold hands, etc. (They also get in the way of the correct placement of your backup lights.)
For all systems, the reliability trade-off boils down to how much you're willing to invest (money - weight - etc) to improve (or elimiante) components to get to your desired system reliability.
Agreed.
QD's are what... $4? Why would I invest $4, and what do I get for the money? LESS system reliability?
That investment doesn't make any sense to me.
Actually, we're researching lightweight composite 3000psi tanks on one project at work...
Yes, that's why I said "of the Romper Room kind" - so that we wouldn't confuse my intended meaning of the word "plastic" with those high quality composites, which are quite a different material.
I am intimately familiar with composite tanks... My local fire station uses them, and prior to a dive shop opening here, I used to get fills at the station.
For walking around on land, they make sense in terms of weight... But the cost associated and limited lifespan are the tradeoffs.
To a diver, the buoyancy characteristics would be no fun at all.
If we cut to the chase on this whole BS regarding QD's and DIR, the brutal reality is that a QD serves no benefit in a caver or similar overhead environment. As such, it merits being eliminated. However, when you're not in an overhead environment, the lower mechanical reliabilty of an introduced QD can be traded-off against its potential advantages for self-rescue and lower likelihood of drowning in an OW setting to come to a different risk-benefit conclusion.
I would agree with you, but I find no problems performing "self-rescues" without any QD's. In fact, I use a continuous harness with no QD's on all of my "recreational" dives where there's no overhead.
In fact, I use a continuous harness with no QD's when I perform my sea rescues - from the squadron's boat. "Likelihood of drowning?" I think not.
Now, if you think that a QD is a solution for a drowning victim, then you're seriously off-base. I can list about 500 reasons why someone might become a drowning victim, and the solutions to the problems... But QD's are nowhere in there.
If you'd like more information on the correct way to don and doff your rig without using a crutch like a QD, then feel free to check out
http://www.deepsouthdivers.org/homedir3.html . For this discussion, I recommend watching Chapter 12. George also does a nice don and doff at the six minute point of Chapter 3. (Which, by the way, opens up with GI3 saying, "Let's look at this open water rig..." This is a rig with no QD's, which is specifically designed for "no overhead" like you were talking about.)
