Do I want a Spare Air

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I am soliciting opinions on carrying a Spate Air secondary air source for emergencies. I am a relatively new diver that is starting to dive down 70 to 90 feet. My primary fear is equipment failure and needing to rely on a buddy. How common are equipment failures at depth? Is the Spare Air a good option for deeper dives?

Do you not have a buddy now? Where and with whom are you doing these 70-90' dives? How did you come to find yourself doing these dives?

I'm thinking that your cart may be a bit ahead of your horse, Steve.
 
Considering bringing a spare air to mitigate immediate, catastrophic out of gas scenarios while scuba diving is like considering bringing a towel as a backup parachute while skydiving. It simply doesn't work like that.

I've been thinking about the "some gas is better than no gas" argument, and while I agree a SA would give you a couple of breaths and therefor would allow you to perform an extended CESA, a lot needs to line up in your favor for this to actually work in real life. Personally, I do not consider an extended CESA a proper ascent strategy, and "some is better than non" is a false perception of safety.
Unless you train CESA regularly, most CESA's are messy to start with, let alone if you absolutely need an extended one to get out a SHTF situation.
If you DO train CESA often enough, you will also be training gas awareness, so you actually are able to avoid the entire situation in the first place.
I guess risking a decompression injury or pressure injury (by performing a most likely messy extended CESA) is preferable to drowning, but why would anybody who is concerned about catastrophic equipment failure choose that as a backup strategy over making a safe ascent?

Keep in mind that running out of gas due to bad gas management is not a black and white event like you might have experienced during OWD training when the instructor closed the valve. Instead of sucking on a vacuum out of a sudden, in reality you feel an increase in breathing resistance, while you still have a few hundred psi left. This is a very noticeable feeling, and should be your (emergency) trigger to consider your ascent options (buddy? start ascending? deploy SA before actually needing it? ready 80 cuft stage?) and take it from there.

Even most real life equipment related out of air scenario's (like regs freezing) are manageable enough to do a safe ascent. Short of an exploding 1st stage while your buddy is too far and you don't have any alternate option there is really no need to consider an extended cesa a viable ascent strategy.

So if you want an alternate air supply, consider why you want it. Look at the scenario's you might realistically encounter, consider how you would like to ascent from those scenario's. Determine the amount of gas you need for those, and make an equipment decision based on that.
 
I've ever heard someone recommend "Not to get a pony bottle." Please, enlighten us and tell us "ALL." the other options.
Cheers.
Well, I own a 3 liters pony bottle, but I carry it very seldom with me during "normal" dives. It requires a lot of effort, first you must have it filled, than you need to carry it along your travel (when allowed), finally you have to attach it to your harness and have it impeding your movements all along the dive.
And it requires tat you have a third compete regulator.
So a pony tank is a good additional air reserve, but it has a number of drawbacks.
But there are good alternatives for having some air reserve to save your butt in case you managed improperly your air consumption.
One is a good, old valve with mechanical reserve. Both my 15-liters single and 10+10 liters twin are equipped with a reserve valve (in the case of the twin, it is tuned to 100 bar but it only work on the right cylinder).
Of course these valves have two posts, and I use them with two independent regs, which covers me also from the case of a reg failure.
And then of course there are twin cylinders, possibly manifolded. They do not need to be too large. A 9+9 liters, or even a 7+7 liters, are compact twins less bulky than a 15-liters single (which is the standard here), providing a much safer tank than the standard single.
All that said, nowadays I mostly dive with a rented cylinder, which is typically 15 liters and double post (so I can use two fully independent regs), but has no mechanical reserve (rental cylinders do not have them anymore since perhaps 20 years). But I dive much shallower than the past...
I consider basically unsafe the PADI-style AL80 (too small tank) with a single valve and a single reg with an octopus. I have seen many divers going low on air with such a configuration. And considering that, for reasons I not understand, most of these guys still use yoke-mounted regs, I also have seen at least three times the O-ring exploding, emptying the cylinder in a couple of minutes.
In conclusion there are several alternatives providing progressively more protection, and I find it appropriate to scale up their usage according to depth and duration of the dive. The pony tank is on the top of that ladder, but is justified only for very serious dives, close to the "tech" boundary.
 
Having been involved in several OOA incidents (not me but my buddy), things get chaotic and can go to crap in a heartbeat.
I might be misunderstanding the above sentence, but if you have been personally involved with a dive buddy that has had "several" OOA incidents (and "several" for me means 3 or more; otherwise I would use the word once or "a couple") then I really hope you have found a new buddy to dive with.

Funny that you would assume all events referenced were the same buddy as I never indicated that they were the same person. But truth is two were the same guy. No, I no longer dive with him.

The third incident was just another guy in a DM-led group I was with who sucked his tank dry in about 15 min on a deepish dive without noticing. The DM handled it but I stayed with them and ascended ready to donate gas if needed.

Given the number of dives you have and being a DM you are fortunate indeed to have never been involved in a real OOA incident.
 
Do you always have great buddies or do you always carry a pony?

The buddies I dive with are great. Trust them with my life! So not necessary. Occasionally I’ll dive with Insta buddies, when I do I always bring a pony.
 
Well, I own a 3 liters pony bottle, but I carry it very seldom with me during "normal" dives. It requires a lot of effort, first you must have it filled, than you need to carry it along your travel (when allowed), finally you have to attach it to your harness and have it impeding your movements all along the dive.
And it requires tat you have a third compete regulator.
So a pony tank is a good additional air reserve, but it has a number of drawbacks.
But there are good alternatives for having some air reserve to save your butt in case you managed improperly your air consumption.
One is a good, old valve with mechanical reserve. Both my 15-liters single and 10+10 liters twin are equipped with a reserve valve (in the case of the twin, it is tuned to 100 bar but it only work on the right cylinder).
Of course these valves have two posts, and I use them with two independent regs, which covers me also from the case of a reg failure.
And then of course there are twin cylinders, possibly manifolded. They do not need to be too large. A 9+9 liters, or even a 7+7 liters, are compact twins less bulky than a 15-liters single (which is the standard here), providing a much safer tank than the standard single.
All that said, nowadays I mostly dive with a rented cylinder, which is typically 15 liters and double post (so I can use two fully independent regs), but has no mechanical reserve (rental cylinders do not have them anymore since perhaps 20 years). But I dive much shallower than the past...
I consider basically unsafe the PADI-style AL80 (too small tank) with a single valve and a single reg with an octopus. I have seen many divers going low on air with such a configuration. And considering that, for reasons I not understand, most of these guys still use yoke-mounted regs, I also have seen at least three times the O-ring exploding, emptying the cylinder in a couple of minutes.
In conclusion there are several alternatives providing progressively more protection, and I find it appropriate to scale up their usage according to depth and duration of the dive. The pony tank is on the top of that ladder, but is justified only for very serious dives, close to the "tech" boundary.
Divers using an AL80, or even an AL 50 which I sometimes use for very shallow jetty dives, would be in no danger of running low on air if they checked their SPG every few minutes. That should be a cardinal rule of diving, giving warning of air consumption higher than anticipated and allowing the diver to adjust their plans to reflect the gas situation. I sometimes carry a small computer, but I rely on my SPG and wrist watch for dives <50 feet. How divers run out of air when they have a functioning SPG is beyond my comprehension. When I was young there were no computers and SPGs were not available. I was acutely conscious of gas usage and limitations, but had only a J valve to rely on. When I got my first SPG sometime in the 70s I thought it was the greatest thing ever invented for scuba. I've never changed my mind. I've never gotten a clear explanation of the reasons for not checking an SPG every 5 minutes or so. Running out of air when an unconsulted SPG has been indicating increasingly limited air remaining qualifies the diver for the Darwin award.
 
I am soliciting opinions on carrying a Spate Air secondary air source for emergencies. I am a relatively new diver that is starting to dive down 70 to 90 feet. My primary fear is equipment failure and needing to rely on a buddy. How common are equipment failures at depth? Is the Spare Air a good option for deeper dives?

in 36 years of diving I have never had an equipment failure at depth. Had a dive staff member damage the o ring in my Din setup but that was on the boat before the dive. Easily fixed.
 
@Mark IV , @tbone1004 ,

Have you guys gone recreational diving in places like Maui? Where there is one guide and the herd basically follows but no one is assigned anyone and it is each diver for themselves? Are you guys into photography? In that scenario, which I believe is quite common (take pictures of pretty fish following a guide around), a pony bottle is a great idea.

That is the reality of a big part of the diving segment. You can't look at diving purely through tec diver eyes. What does much of the market do? It sure ain't tech diving.

those types of dives need to be considered solo dives and you have to approach it from a solo diving mentality, which is not appropriate for the beginners forum and is a completely different approach. If someone came in and said "hey, I do a lot of solo photography at 100ft, would you recommend a pony because I can't/don't want to work with doubles/sidemount, then sure a 40cf bailout bottle is appropriate". That wasn't this discussion though.

If it’s not too far off topic, I have a question about pony bottles:

This summer on the way to and from a non-diving family get together, I will have a couple days of diving in the Carolinas (one day in each Carolina).

These will be boat dives to about 100 feet. I don’t have a buddy to bring, so I’ll be randomly paired (but I won’t show my DM card so as to avoid baby sitting someone who shouldn’t be there).

Given the depth, conditions that may be rougher than I’m used to, and likelihood of an unreliable buddy, I was thinking about taking the self-reliant diver course and buying a 19 ft^3 pony.

I’ll be diving with single steel 120’s.

Wisdom or prudence of this idea? Other suggestions?

Conditions off the coast are usually only bumpy at the surface, once you get down they're pretty chill. Plan dive properly so you can get back to the anchor and you'll be fine. Taking the self-reliant diver course depending on the instructor is not a bad idea though.

I suppose......:letsparty: I should clarify.....a little.
The "Spare Air." even on its initial release was highly criticized, and "Yes, I believe it was manufactured purely for the market, and to rake in the cash.
I do not consider a "Spare Air." a pony bottle. (Sorry, I just don't.) I dove with a 30 cubic in between my doubles for many years,
I currently own (3) 40 cubic bottles. So, should you buy a "Spare Air." I would say "No."
Should you buy a "Pony Bottle.".......I highly recommend it.
Cheers

why on earth would you put a 30cf bottle in between your doubles?

Hello. I typically dive singles.....Faber L.P. 121's and Faber H.P. 120's
In 100ft, I would recommend a 30 cubic bottle.
Cheers.
why a 30cf? 40's handle much easier in the water. Basically same diameter, couple inches longer, but they have the same buoyancy characteristics when full so they "feel" the same when full and give you a third more gas. When they are less full, they get more floaty which makes them easier to deal with.


Also, to anyone using pony bottles that are slung, for the love of all that is holy please sidemount them with a loop bungee. I have some pictures and responses on here about sidemounting deco/bailout bottles for rebreathers and how I got the loops on there. Please look at them. It takes 10 minutes to set up but it makes all the difference in the world
 
You must not have met any technical divers, certainly not any DIR divers. Within that realm, you trust your buddy and use your buddy as your backup for recreational level diving, it's part of the team mentality. Once you need true redundancy for things like decompression/overhead then you are into sidemount/doubles where you have proper redundancy.
If you don't trust your buddy, then you are basically diving solo which is not relevant to this part of the forum. That said, even when solo diving, with proper planning, you shouldn't ever need one because of reasons I mentioned above on why I don't use one.

Again, one important thing. Pony bottles are great for selling gear. If they were truly that beneficial for safety, then they would be required by the agencies when teaching because as an instructor you are inherently solo diving. No agency requires or even recommends that instructors dive with a pony bottle and in fact, most mandate that you are in similar equipment to your students. I.e. I'm not supposed to teach open water students in backmount singles while diving sidemount. If you dive a pony properly, then you don't have a secondary second stage on your main tank because 3 second stages is ridiculous, and at that point you are no longer diving similar to students.
Pony's are also not required nor recommended for deep training. Since not a single agency advocates their use, then we have to look at why people feel the need to use them and fix those reasons. For solo diving, it's a different discussion, but solo diving is not appropriate to discuss in depth in the beginner forums
This completely ignores cold water diving, where free flows are a possibility. It’s common here in the Great Lakes to see single tank divers with Alu 30s or Alu 40s tanks side slung on deeper dives where even in the summer, temperatures below the thermocline can be 40F or 42F. Ice crystals stick the diaphragm open in a cold water free-flow.

Having an attentive buddy donating a working regulator doesn’t mean that your troubles are over. Over breathing the donated regulator while the attentive buddy is also breathing off the other regulator can place too much of a demand on the buddy’s regulators in such cold water. And now you have another free-flowing regulator or two. And two divers in a more stressful situation.

This is where having a side slung Alu30 or 40 is a real peace of mind. You just switch to the redundant tank and end the dive. Like everything else in this sport, divers need to practice deploying and stowing the slung tank regulator; it is not difficult.

Your attentive buddy can assist you in turning off your back tank so it doesn’t continue to annoy with noisy bubbles and deplete the entire tank as you ascend.

Sometimes turning off the tank and waiting a few minutes is enough to stop the cold water free-flow, the ice crystals get a chance to melt, and cautiously turning the back tank valve open means the fee-flow is solved.

But other times the second stage is completely frozen open and the tank gets depleted unless it is shut down. The dive is over.

A side slung Alu 30 or 40 is really helpful when you have an inattentive buddy, which happens more than we’d like. Just switch to the redundant tank, and you can get your inattentive buddy’s attention and end the dive.

And while a free-flowing reg is noisy, and obscures your vision with multiple bubbles, in warm water you can breathe around it if you try. In cold water you have a mouthful
of ice crystals.

For an average OW or AOW cold water diver here in the Great Lakes (or anywhere else with cold water) a side slung Alu 30 or 40 *is* best practice.
 
This completely ignores cold water diving, where free flows are a possibility. It’s common here in the Great Lakes to see single tank divers with Alu 30s or Alum40s tanks sideslung on deeper dives where even in the summer, temperatures below the thermocline can be 40F or 42F. Ice crystals stick the diaphragm open in a cold water free-flow.

Having an attentive buddy donating a working regulator doesn’t mean that your troubles are over. Over breathing the donated regulator while the attentive buddy is also breathing off the other regulator can place too much of a demand on the buddy’s regulators in such cold water. And now you have another free-flowing regulator or two. And two divers in a more stressful situation.

This is where having a side slung Alu30 or 40 is a real peace of mind. You just switch to the redundant tank and end the dive.

Your attentive buddy can assist you in turning off your back tank so it doesn’t continue to annoy with noisy bubbles and deplete the entire tank as you ascend.

Sometimes turning off the tank and waiting a few minutes is enough to stop the cold water free-flow, the ice crystals get a chance to melt, and cautiously turning the back tank valve open means the fee-flow is solved.

But other times the second stage is completely frozen open and the tank gets depleted unless it is shut down. The dive is over.

And while a free-flowing reg is noisy, and obscures your vision with multiple bubbles, in warm water you can breathe around it if you try. In cold water you have a mouthful
of ice crystals.

And for an average OW or AOW cold water diver here in the Great Lakes (or anywhere else with cold water) a side slung Alu 30
or 40 *is* best practice.

Bingo. And this is why I sling an AL40 on single tank Great Lakes dives.
 

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