Does my rig default me as a "Bad Buddy"?

[CT-Rich]

By making sure that neither you or your buddy ever run out of air, and by following your OW training if you do.

With the possible exception of a couple of astonishingly rare failures (clogged dip tube and an exploding first stage), there is absolutely no legitimate reason for either you or your GF to ever run out of air.

However assuming someone was dumb enough to run out,....

Working under the assumption that only an idiot would run out of air is like saying "only an idiot would have a car accident... Why bother with a seatbelt?"

Pooh happens. You train/equip for the exceptional not the average. He is asking what is a safe effective system so that he and his GF walk away from a wreck. People get stuck in odd situations, a o-ring bursts at depth, a gauge is faulty a HP hose ruptures. Saying it shouldn't happen is a sad excuse to say don't bother to cofigure your rig in proper configuration. If you are sure you aren't going to end up the idiot in an OOA, feel free to get rid of your octo, and the quick release on your weights, your SMB, safety whistle and any other cluttery junk on your rig. Just don't dive with me.

---------- Post added November 25th, 2012 at 06:36 PM ----------

BTW, I know everyone hates them but I'm buying a spare air for her as well. Better to have a limited amount of air than no air and it will give her time if we get separated so I can then donate and get her to the surface.

As has been pointed out, a spare air is pretty much useless. A couple of extra breaths are better spent heading up than to another diver. If you or her are going to carry another bottle of air, look into getting a pony bottle with enough air to get you to the surface. I would rather trust luck on a free ascent than the false sense of security provided by spare air. At least I have a clear understanding of just how badly my pooch is screwed....

 

[GrumpyOldGuy]

BTW, I know everyone hates them but I'm buying a spare air for her as well. Better to have a limited amount of air than no air and it will give her time if we get separated so I can then donate and get her to the surface.

IMMO, a spare air is a CESA assist device, not a small pony. The only things you can count on it to do extend the depth that you can execute a CESA from. The extremely limited amount of air does not give her time to do anything but bolt for the surface and deal with the side effects of the fast ascent later......

If you true love and value her, just plant your butt next to her, monitor your air and be a good buddy.

 

[Tigerman]

...
Pooh happens. You train/equip for the exceptional not the average. He is asking what is a safe effective system so that he and his GF walk away from a wreck. People get stuck in odd situations, a o-ring bursts at depth, a gauge is faulty a HP hose ruptures. Saying it shouldn't happen is a sad excuse to say don't bother to cofigure your rig in proper configuration.
..

Actually a ruptured HP hose would be a non-event other than the fact that its a loud bang and a loud hiss - The diameter of the HP hose is too small to let air out very fast. Other than that, I completely agree.

If youre not convinced, theres a very visual video of it on youtube
[video=youtube;2-dhP_jSO6I]http://www.youtube.com/watch?v=2-dhP_jSO6I[/video]

 

[AaronRiot]

Hmm... the video above is in a shallow pool... would it not be a danger at 100+ft and with a partially used tank?

 

[GrumpyOldGuy]

Hmm... the video above is in a shallow pool... would it not be a danger at 100+ft and with a partially used tank?

No. There is a literally a pin hole in the reg that only allows a small amount of air to pass through in the event of a HP hose failure. You could sever the hose and continue the dive as normal, except that you would have no SPG reading.

 

[flots am]

Working under the assumption that only an idiot would run out of air is like saying "only an idiot would have a car accident...

Since running out of air is most comparable to a single-car accident, I'd have to agree with you.

This isn't to say that a redundant air source is bad, but comparing a spare-air to a real, properly sized pony bottle is like comparing a St. Christopher Dashboard Statue to 6-side airbags and a seat-belt.

One makes you feel safer the other actually makes you safer.

flots.

 

[chrpai]

The video said it took 35 minutes. So let's assume 1000 psi half used tank... that's 12 minutes. Now let's assume 100ft that's 3 minutes. Not the end of the world.

 

[eponym]

OP:
You're only a "bad" buddy if you won't make agreements on the surface or hold to them once underwater. Or if you're an a$$ from the get-go.

I was once gearing up (necklace bungee for my octo under my chin, I donate the primary) and had another diver on the boat stroll up to me and declaim, "Boy, no one's going to get YOUR octo from you, are they?"

Not my buddy. Not by a big margin.



PS. Here are some drain times for an 80 cu.ft. 3000 psi tank during tests conducted in advanced training:

burst disk failure any depth 72 seconds
ruptured LP Hose any depth 83 seconds
ruptured HP Hose any depth 22 min
second-stage free-flow surface 255 seconds
second-stage free-flow 100 fsw 155 seconds

Your results will vary.

 

[CT-Rich]

Hmm... the video above is in a shallow pool... would it not be a danger at 100+ft and with a partially used tank?

The pressure differential between 100+ and the inside of the tank and 10ft is neglible. The pressure at 100ft is 4 ATM or about 60 PSI, the inside of the tank is 3000 PSI. It would make a difference but so small as to be irrelevent. The real danger would come if it happened when you had a deco obligation, then it would a much bigger worry. Of course if you want to save air, breath directly off the air streaming from the HP hose. More than enough coming out that way to breath. Just form a cup with your hand over the hose end and your mouth and breath off the little air pocket that is created. We did that off a bare tank in my Basic SCUBA class in 1980.

 

[GrumpyOldGuy]

The video said it took 35 minutes. So let's assume 1000 psi half used tank... that's 12 minutes. Now let's assume 100ft that's 3 minutes. Not the end of the world.

Minor point, the rate the gas is lost through the high pressure hose varies with the tank pressure.
I.E. The lower the tank pressure, the lower the volume (rate) of gas loss, so its a lot longer than 3 minutes on the bottom 1000'