Recently I got the chance to test the Spare Air Model 300, the “smallest, most compact redundant emergency air system available” in the pool at work. Spare Air is a 3.0 cubic ft pony bottle with a built in regulator which is simple to attach to one’s BCD and according to their website “puts self-rescue at your fingertips”.
Each Spare Air unit comes with a refill adapter that hooks the bottle to an yoke valve (commonly found on aluminum 80 scuba tanks) so you can fill it without having to take it to a dive shop. I preceded to fill my test bottle and watched as the little white pin on the side popped out to indicate the tank was full. I then mounted the Spare Air to my BCD using the supplied holster and dove down to the deep end of the pool. Now I’m not sure if it’s because the device hadn’t been used in a long time or it’s a failing with the device itself but my first dive using the Spare Air was anything but pleasant. At 14′ deep I got about 20 breaths of air but each breath was difficult and uncomfortable. I found it more difficult to breathe off of than a rental octopus! It wasn’t pleasant but it worked.
For some reason on the second pool dive, it was much easier to breathe off of the built in regulator but again I was surprised to only get about 20 breaths. For disclosure purposes: I’ve been diving for a few years, I’m fit and I consider myself to be good on air consumption. I’m not a heavy breather and at no time when I was using the Spare Air was I in a panic. So the second pool dive was better in terms of the ease of breathing but I didn’t gain any more time underwater.
Here’s where the problems for this little pony bottle began to surface:
- I got about 20 breaths at 14′. This means I’d likely get less than 15 breaths at 33′ or 10 breaths at 66′. Since I more likely to run out of air (and need a pony bottle) on a deep dive and I’m likely to be panicked, I’d barely get to the surface before this bottle would be empty. The whole point of a pony bottle is to get a diver safely to the surface when you’re out of air. Safely means your pony bottle should allow for any safety stops that may be required. Otherwise you could just perform a CESA.
- This device is like most scuba cylinders and needs a visual inspection every 2 years. The Spare Air has it’s visual inspection label on the bottom of the tank. Unfortunately this bottle can’t be visually inspected by most dive shops since they won’t have the tools necessary to open and view it. This means it’s going to be harder and more expensive to maintain.
- The final problem with the Spare Air pony bottle is it’s high cost. The 3.0 cu ft Spare Air retails between $200 and $300. For $100 you can get a pony bottle 2-3x larger in size and for another $100 you can get a perfectly good, albeit used, regulator. This means for less money you can build your own bigger, better (but less compact) version. Perhaps if it was priced between $50-$100 it might make more sense but even then it would only be useful for skin and free divers who want a little extra time.
As a side note: Most divers that work in a professional setting, like those in dive shops, will not recommend buying a Spare Air cylinder because it gives the diver false hope. If you carry a pony bottle and are not diving deep (65′ or less) you may be inclined to push your air consumption limits and you risk running out of air even sooner. The false hope is the Spare Air can bail you out if you empty your tank due to carelessness. If you do dive deep (greater than 65′) you still run the risk of emptying the Spare Air cylinder before you reach the surface and you may be more inclined to hold your breath and/or not follow traditional safety precautions when surfacing.