This ought to Work Several of you into a Frenzy

[Doc]

Who here is concerned about running out of air at 30'?

Tell me of this ice diving you have just outside of your igloos.

 

[lexvil]

Spare Air 300 and Spare Air 600: ScubaLab Field Test

 

[mi000ke]

Spare Air 300 and Spare Air 600: ScubaLab Field Test

I suppose that's reasonable if you are doing a shallow dive (< 60 ft) and don't get too rattled when the SHTF. But coming up from 100', assuming a minute at depth to sort things out, then ascending at 30 fpm to 15' for a safety stop (which I would do assuming I had the air), then up to the surface, I come up with a time-weighted average depth of about 45'. And given my reasonable SAC rate of 0.4 cfpm, I compute I would need 7 cu ft of air - and then doubling it for stress and safety says I'm sticking with my 13 cf pony when I'm not diving with reliable buddies.

 

[lexvil]

I suppose that's reasonable if you are doing a shallow dive (< 60 ft) and don't get too rattled when the SHTF. But coming up from 100', assuming a minute at depth to sort things out, then ascending at 30 fpm to 15' for a safety stop (which I would do assuming I had the air), then up to the surface, I come up with a time-weighted average depth of about 45'. And given my reasonable SAC rate of 0.4 cfpm, I compute I would need 7 cu ft of air - and then doubling it for stress and safety says I'm sticking with my 13 cf pony when I'm not diving with reliable buddies.

While agree with the concept of the 13cf pony I recently had a full blown (as in blown out seat) second stage failure, granted at 42 ft but full flow now stopping it or slowing it down failure, I had either a 19 or 13 pony which I didn’t even bother with and in 40 seconds I was on the surface, I don’t know what I would have to be doing to spend a minute sorting things out

I think even at 100+ ft the 6cf would get me to the surface with air to spare, safety stops are not in the plan for an emergency, for me anyway preferring a chamber ride to drowning. I don’t own a spare air but also don’t disparage those that do, costly compared to a 13cf pony even when you factor in another regulator but not worthless by any means. I now have an in-line shutoff for my experimental second stage testing, I would rather finish the dive than do that surface swim across the kelp fields.