Spare Air

[lamont]

I'm a bit lost. Sure a pony would have let you do that...and easily. But, why wouldn't a Spare Air have enabled you to do the safe ascent bit ... assuming you were not beyond 60 feet deep?

By 'safe ascent' i mean not blowing by stops. i don't view safety stops as optional. from 60, 1 min to 30 and 3 mins to 0 is going to take more than 4 cu ft of gas and the spare air doesn't have enough...

Still, i was only at around 35 fsw at max depth, but still in the event of a free flow going onto a pony bottle and trying to fix your backgas before surfacing is considerably more elegant than only having the time until your backgas drains and your spare air drains to try to fix the issue. even an Al19 would give you at least 10 minutes at that depth. I don't like putting myself in the situation where I can wind up with only a few minutes of gas at depth, that is cutting it way too close. If you screw up at that point (and screw ups often happen on top of failures) you run completely out of gas -- and if you read DANs report on fatalities that and buoyancy control issues are the leading issues involved in fatalities.

 

[Rev. Blade]

Things I carry on all my dives, but hope to never need:
Knife
Shears
Whistle
Second Regulator
Safety Sausage
Strobe
Spare Air
(I have deployed all these things until I'm comfortable with them. The only one that needed a couple tries to "get it right" was the sausage.)

Of the things on that list, the only thing that might be easier to deploy than my spare air, is the whistle that is zip tied to my inflator hose. People who count on their Spare Air a backup dive cylinder, must not understand what they have. It holds a lot less air than they plan to "waste" by getting back on the boat with at least 500 p.s.i. If I have my SA out for anything but practice, I'm in an emergency. If I screwed up BIG TIME, and don't know where my buddy is, I'd take a few seconds to see if that redundant air source was my closest air. If my buddy was (for some unforgivable reason) not close, I'd head for the other redundant air source... the surface. My SA is not for "diving", it's for bailout I plan to never use... except to practice.

If I was ever going to do a CESA, I'd like to know I was going to start with (at least) one full breath.


Things I carry on most of my dives, but sometimes get left behind:
Primary sized flashlight
Backup flashlight
Dive slate
Rubber darts (in case I want a toy to fling) from the pool department

The only divers I've seen who practice with their emergency gear (outside of classes) were practicing with me... and only because I asked them to.

 

[Rev. Blade]

By 'safe ascent' i mean not blowing by stops. i don't view safety stops as optional. from 60, 1 min to 30 and 3 mins to 0 is going to take more than 4 cu ft of gas and the spare air doesn't have enough...

Still, i was only at around 35 fsw at max depth, but still in the event of a free flow going onto a pony bottle and trying to fix your backgas before surfacing is considerably more elegant than only having the time until your backgas drains and your spare air drains to try to fix the issue. even an Al19 would give you at least 10 minutes at that depth. I don't like putting myself in the situation where I can wind up with only a few minutes of gas at depth, that is cutting it way too close. If you screw up at that point (and screw ups often happen on top of failures) you run completely out of gas -- and if you read DANs report on fatalities that and buoyancy control issues are the leading issues involved in fatalities.

I absolutely agree that making your ascent slower than 30 feet per minute, and doing your 3 minute stop is safer than "blow and go". Agencies used to teach 60 feet per minute, and no stop... but slower and stopping makes for a safer dive.

I've seen divers make a mad break for the surface because they were "out of air" with 700 psi. It's as if they did not understand you don't die when your tank gets to 500, even if you're still under water. The point of being on the ladder with 500, is to give you a cushion, in case you fouled up. You really can breathe the last air. It's just stupid to use it in your dive plan.

For what it's worth, I've never been back on the boat with less than 450... and yes I had to buy everyone on the boat a beer (end of the day) because I had messed up.

 

[Doc Intrepid]

A piece of gear is rarely inherently "good" or "bad".

It is either "useful" or "not useful" given your personal, specific dive plans.

The salient points are that:

1. During emergencies most diver's respiratory rates increase dramatically; and

2. Spare Air's don't offer much spare air.

As most divers don't measure their respiratory rates after an "Aw Crap" revelatory moment, they seldom appreciate that thereafter they be consuming over 1 cubic foot of gas per minute during their response activities.

If these involve a bolt to the surface from 30' or 40', a spare air may suffice.

If anything were to impede their progress, even excessive depth, it may NOT suffice.

Generally its considered prudent to hope for the best and plan for the worst...with a spare air you're not often planning for "the worst".

OTOH, perhaps you rarely dive deeper than 40' - 60', and you'll have no issues using a spare air during a direct ascent.

Its really dependent on the diver, and the dives that diver is doing...

Best,

Doc

 

[ItsBruce]

By 'safe ascent' i mean not blowing by stops. i don't view safety stops as optional. from 60, 1 min to 30 and 3 mins to 0 is going to take more than 4 cu ft of gas and the spare air doesn't have enough...

Still, i was only at around 35 fsw at max depth, but still in the event of a free flow going onto a pony bottle and trying to fix your backgas before surfacing is considerably more elegant than only having the time until your backgas drains and your spare air drains to try to fix the issue. even an Al19 would give you at least 10 minutes at that depth. I don't like putting myself in the situation where I can wind up with only a few minutes of gas at depth, that is cutting it way too close. If you screw up at that point (and screw ups often happen on top of failures) you run completely out of gas -- and if you read DANs report on fatalities that and buoyancy control issues are the leading issues involved in fatalities.

Thanks. A good argument for the pony. I'll consider it, but can't promise I'll start carrying one on 60 fsw dives.

 

[birdwrasse]

where do you carry it Bruce? Do you have the big one or the small one?

...you know men always carry a "large" pony bottle...


:lol:

 

[Bigcape]

Why would anyone use a 3cf bottle for anything except for trying to find your keys or sunglasses that you dropped over the boat or on the dock in shallow shallow water or getting a rope untangled from your boat prop.

Any body who thinks a minute of air at best is the "something is better than nothing" then they ought to quit diving altogether or go back to OW class and start over

Now a 19cf at minimum will give to time to calmly doff and don or surface in an 1:1,000,000 chance of total equipment failure NOT 3cf!

 

[trucker girl]

Things I carry on all my dives, but hope to never need:
Knife
Shears
Whistle
Second Regulator
Safety Sausage
Strobe
Spare Air
(I have deployed all these things until I'm comfortable with them. The only one that needed a couple tries to "get it right" was the sausage.)

Of the things on that list, the only thing that might be easier to deploy than my spare air, is the whistle that is zip tied to my inflator hose. People who count on their Spare Air a backup dive cylinder, must not understand what they have. It holds a lot less air than they plan to "waste" by getting back on the boat with at least 500 p.s.i. If I have my SA out for anything but practice, I'm in an emergency. If I screwed up BIG TIME, and don't know where my buddy is, I'd take a few seconds to see if that redundant air source was my closest air. If my buddy was (for some unforgivable reason) not close, I'd head for the other redundant air source... the surface. My SA is not for "diving", it's for bailout I plan to never use... except to practice.

If I was ever going to do a CESA, I'd like to know I was going to start with (at least) one full breath.


Things I carry on most of my dives, but sometimes get left behind:
Primary sized flashlight
Backup flashlight
Dive slate
Rubber darts (in case I want a toy to fling) from the pool department

The only divers I've seen who practice with their emergency gear (outside of classes) were practicing with me... and only because I asked them to.

Very well said IMO. Thank you.

 

[trucker girl]

OTOH, perhaps you rarely dive deeper than 40' - 60', and you'll have no issues using a spare air during a direct ascent.

Its really dependent on the diver, and the dives that diver is doing...

Or a deep dive with an O.S. moment in a shallower area. Or as The Red Head pointed out- any time you might have an air-related O.S. moment and need to get to your buddy (who for whatever unforgiveable-thank you Rev Blade- reason is just a bit too far away).

All of which means you screwed up... not that you planned to depend on some puny air bottle to save you from the depths of stupidity and incompetence.

 

[trucker girl]

While I absolutely agree that the testimonials you guys have posted from Spare Air (though I have not checked out the site myself to verify them) are ridiculous and cross the border into promoting incompetence...

These statistics you keep giving... 95% of divers won't deploy it correctly etc... where are you getting these? Are these off the top (95%) of you head? I am serious here- not trying to be a smart ***... has there been any sort of study done- though I don't see how you could really do a study like this and have any sort of accurate results unless it was very large.

It seems to me that 95% of statistics are made up on the spot 95% of the time.

Has anyone ever died while using a Spare Air? I won't be surprised to find the answer to be yes... but are you basing you statements on facts?

And if they died while using the Spare Air... was Spare Air at fault?

To lump all divers who intent to sport a S.A. together into one big group of overconfident duds seems fairly condescending IMO. Maybe "95%" of them ARE overconfident duds... maybe 15% of them are and the rest of the 85% of Spare Air sportin' divers are actually prudent.

I tested mine today at 30 feet (sorry- it was 45 degrees at 54 feet and I'm not interested in freezing my butt when I test it) and got right at 30 breaths out of it.

As Rev. Blade pointed out... if I EVER deploy it for anything OTHER than a test then someone screwed up big time... most likely ME. So can I be allowed into the 5% of divers who aren't overconfidend duds now?