Spare Air

[DivingDoc]

Has anyone actually tried to ascend from 130 fsw using only their spare air?? What is the depth below which people feel you should use a pony instead of a Spare Air as an independant alternate air source?

Diving Doc

 

[Kaufdropp]

The only time i ever had to use mine was from 80 feet and i used about 3/4 of it. I would recomend a pony bottle

 

[DivingDoc]

But if you only used 3/4 or it from 80 feet -- that was a succes, right? It's only a failure if you used it all up and still had more feet to ascend from, right?

 

[Diver Dennis]

There was someone else on the board who, as an experiment tried an ascent with their Spare Air. I'll look for it but if I remember correctly, they did not get too many breaths off of it.

 

[Thalassamania]

They claim 3.0 CF - 50 Breaths at the surface. What's your SAC rate? Use the average depth of 75 ft and figure it out your self.

For me, with a SAC of 0.5, I'd get about 1.8 minutes out of a spare air (at 75 feet). That means that I'd have to ascend at about 70 ft/min for it to work. If I made a controlled ascent at 30 ft/min (without doing the calculus) I'd make it to not quite 85 ft. before I ran dry.

IMHO: Waste of time. Waste of money. Dangerous as hell. Only useful for getting out of a helicopter that goes down over water.

 

[TheRedHead]

I've often wondered if a better application of spare air would be an extra few breaths to make it to your buddy in case of seperation. Not that I would ever use Spare Air or advocate the use, but just a thought....

 

[ItsBruce]

A spare air is better than nothing ... which is why I've started carrying one. It will get me to my buddy at any depth at which I will dive. It will get me to the surface from most depths at which I will dive. I have no intention of schlepping a pony for any "normal" rec diving.

 

[Cacia]

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

 

[HowardE]

There was someone else on the board who, as an experiment tried an ascent with their Spare Air. I'll look for it but if I remember correctly, they did not get too many breaths off of it.

It was me... I tested a 3 cf spare air at 30 FSW, and sucked it dry in 3 1/2 minutes - in a relaxed state - 22 breaths. Do the math. There won't be much air in your spare air at 130'

If you're diving to 130' and relying on a spare air, so that you can stay down longer... either get a bigger tank, or don't stay down so long.

 

[HowardE]

I've often wondered if a better application of spare air would be an extra few breaths to make it to your buddy in case of seperation. Not that I would ever use Spare Air or advocate the use, but just a thought....

I would imagine that if you tried this, the average diver would be in a panic - "find my buddy" mode, and waste precious gas for a somewhat speedy ascent.