Hi Lou,
I and many use Spare Air as a bail out bottle, the 2.7 cF one. I am not a qualified freediver ( maybe 5 more years
) but a recrational scuba instructor ( I gave up teaching long ago ). I live in the tropics and dive very light. This small air supply can save life ( in non deco state ) if you are say from 120 feet. This is about the maximum depth u can push with safe ascend rate. Remember I dive very light, only 2 kg of lead, 3mm polartec wetsuit and a single 80CF aluminum tank.
I don't know ur breathing rate but for me and all of my friends, this is a very useful bail-out bottle, no deco, no dive time extension............a do or die small bottle.... exactly how it is designed to be.
As for freediving, if you are hunting, I will personaly reccomend the Spare Air, we know that the line entanglement and other possible danger exist in much bigger proportion than if you are freediving to just be in the depth for pleasure. Again, as Mr. Etzel mentioned, you better do not assume that you are actualy carrying one to extend ur bottom time. This spoil the sport.
One might look at you a less macho freediver with those tiny bottles but if safety is most important to you, I don't see any fault of having small insurance tucked on ur weight belt. If you have a buddy pased out and sank deep, this tiny bottle might be the only instant solution to that emergency situation, unless you are sure that your skill and physic can handle the drag of a second diver from deep water, but how sure is sure until it happened ?
By carrying one of this small bottle the only damage is ur ego, if you keep sucking air out of it for dive time extension, then it will be best to scuba. Is it wrong to be extra cautious ? You choose.
A simple analogy is like a fighter pilot, is he wrong to carry a parachute ? He has a do or die job too. Do you put on a seat belt when you drive ? Does this seat belt make you look like a less capable driver ?
You are a scubadiver. We were taught how safety is above everything else. I see freediving differently, with many daring individuals ( the number is increasing ) trying to set world records ( of which a few died ), this is extreme sport if you push it. We can't blame them for whatever goal they are trying to set, it's their live and pride.
This is just my opinion. Hope my view help.
P.S Spare Air in my experience is not as reliable as say a US Diver reg. It's weakness is a very mild leak. It combined first stage and second stage in one seat design ( maybe the year 2002 model is different ). Don't ever purge this unit forcefully and always try to see escaping bubbles underwater, just in case there is a minor leak. Good luck.
IYA
