Should I get a Spare Air?

[zeN||]

Man, don't listen to these self-proclaimed ex-spurts who diss spare air, it is meant to GIVE YOU A FIGHTING CHANCE nothing more, believe me, when you are 60 feet + and out of air, those 10-20 breaths will save your ass (and maybe keep you from passing out, which is almost certain death), there are a million reasons why you could get into an ooa scenario, spare air works well for more shallow depths, where you don't want the added weight and drag of a larger pony bottle (or don't need more volume) cheers, zeN}}

 

[SeaFlea]

for your thoughts. I figure a few breaths is better than none so with that said Spare Air would be beneficial. But I'm disturbed about all the comments about Spare Air's dependability. I tend to spend more for my equipment because I want it to function when it counts. It seems to me the quality just isn't there.

Thx again everyone.

 

[agstreet]

zeN|| once bubbled...
Man, don't listen to these self-proclaimed ex-spurts who diss spare air, it is meant to GIVE YOU A FIGHTING CHANCE nothing more, believe me, when you are 60 feet + and out of air, those 10-20 breaths will save your ass

Actually, it won't give you 10-20 breaths at 60 ft (more like 4 or 5 when you're in full on panic mode), and it wasn't designed for scuba rescue at all. Spare air was originally designed as a rescue breathing apparatus for pilots who had to ditch over water. For that application it's perfect. Then the marketing wonks got ahold of it and decided to "expand the market" and sell it to unsuspecting scuba people. It's managed to save a couple of people in spite of it's terrible shortcomings, which gave the marketing wonks a little bit more ammunition in the form of testimonials. That doesn't change the fact that it's a terrible band-aid approach to OOA emergencies.

 

[zeN||]

Well gunpowder was originally created for fireworks, so what? Seaflea, spare air is 3.0 cf of air, manufacturer rates it at 57 breaths at surface (less at depth), you don't have to be one of these "ex-spurts" to figure that one out 'nuff sed ~Z

 

[scywin]

Anyone seen or used an Aquavit unit? Any opinions to share? Any knowledge of how an airline would deal with such a unit?

 

[scubafanatic]

...do the math:

per : http://hypertextbook.com/facts/2001/LaurenCalabrese.shtml

total lung capacity of a healthy young adult = 6 liters

vital capacity = 75% of total lung capacity = 4.5 liters

(vital capacity is the air consumption reached during strenuous exercise...i.e. a panicked diver OOA situation)

Spare Air = 3 cu. ft = 85 liters (@ 1 cu. ft. = 28.3 liters)

....so, on the surface @ 1 ATM, under high exertion, the average young adult will get 19 breaths before emptying a 3 cu. ft Spare Air. ( 85 liters/ 4.5 liters per breath= 19 breaths)

...and @ 33ft deep (2 ATM) the average young adult will get about 10 breaths.

........and @ 66 ft deep (3 ATM) the average young adult will get about 6 breaths.

......and @ 99 ft deep (4ATM) the average young adult will get about 3 breaths.

I don't suppose such calculations are included in the Spare Air sales brochures.


Karl

 

[mrducks]

NO NO NO NO NO!!!!!!!!!1
do not waste your time with a spare air! it is a POS.
mrducks
30 years diving exp. trimix/cave certified

 

[Sean326]

I bought a 3 cuft. spare air and tried it last weekend....

My buddy and I went down to 95' and I simulated an OOA situation. I exhaled, took out my primary, took 20 seconds to simulate messing with my reg brought my backup reg to my mouth (but i didn't inhale). then i pulled out my spare air and started a CSA.

I tried to control my breathing safely, I didn't add air to my BC, and I kept an eye on my computer and kept my ascent rate at 100% to 120% I ran out of air at 35'.... good for about 4 breaths

If I was really out of air I probably would have been more agressive and dropped my belt but I also would have been more panicked. (it was just a fun test I wasn't going to risk getting hurt)

In summery I have turned my spare air over to my kids as a really cool pool toy and will be getting a 13 cuft pony bottle.

For those of you who say having a backup does more harm than good...

1, most NJ dive boats require a completely seperate and redundant source, so it's either dive doubles with an isolation valve or have a pony.

2, In my life experience having a spare anything is better than not. a poster once wrote that having a backup makes you more likely to have an OOA situation well... I never thought that having a spare tire in my car made it more likely for me to get a flat

 

[Don Burke]

Sean326 once bubbled...
I bought a 3 cuft. spare air and tried it last weekend....

My buddy and I went down to 95' and I simulated an OOA situation. I exhaled, took out my primary, took 20 seconds to simulate messing with my reg brought my backup reg to my mouth (but i didn't inhale). then i pulled out my spare air and started a CSA.

I tried to control my breathing safely, I didn't add air to my BC, and I kept an eye on my computer and kept my ascent rate at 100% to 120% I ran out of air at 35'.... good for about 4 breaths

If I was really out of air I probably would have been more agressive and dropped my belt but I also would have been more panicked. (it was just a fun test I wasn't going to risk getting hurt)

In summery I have turned my spare air over to my kids as a really cool pool toy and will be getting a 13 cuft pony bottle.

For those of you who say having a backup does more harm than good...

1, most NJ dive boats require a completely seperate and redundant source, so it's either dive doubles with an isolation valve or have a pony.

2, In my life experience having a spare anything is better than not. a poster once wrote that having a backup makes you more likely to have an OOA situation well... I never thought that having a spare tire in my car made it more likely for me to get a flat

You're the first person I know of to actually try this and then go public with the results.

I appreciate your candor.

I've been telling people to divide the time they get from an AL80 by 26. That's what a 3 cuft bottle does for you.

Will 13 be enough? I went to small doubles so it isn't an issue for me.

 

[Sean326]

Don Burke once bubbled...
Will 13 be enough? I went to small doubles so it isn't an issue for me.

Your right to question the 13cu. , I'm thinking based on my experiment that if my spare air was a 6cu., I would have made it up so I'm guessing that a 13 should get me to 15 ft. and even let me hang out for a safety stop.

My goal with the pony is to find a nice compromise between size and utility to make a part of my local dive rig.

On the longer deeper wreck dives I will either double up and isolate my 120s. or just get a set of 100s as a dedicated double set. (my single 120s are set up so i can just attach the isolation valve and make them doubles but i have not as yet)