Pony bottle skills

[doole]

defending people who dive a leaking butt-mounted pony bottle that they can't reach the valves and which might be turned off with no SPG and no idea of how much air is in there puzzles me. or were you not intending to defend those people? because that's all I was addressing...

...not even remotely close to what I was suggesting. just make sure that when you hand me that yellow octo that there's air in your pony and its turned on, or i'm going for your primary...

God love ya, Lamont.

If you had your own show, I'd watch it. This was almost as good as the neon pink fin comment...

 

[TooTall]

I dive with a bunch of photographers who get focused (pun intended) on the right shot and wouldn't know if there was a problem with the buddy half the time. Most of the time the photographer is leading the way hoping to sneak up on something before it gets spooked away. So if I had a problem it might not get noticed right away by my buddy.
I too am looking at a pony setup in the near future for several reasons. I have been looking at the 13 cu ft because:
1)it is small and can be handed off.
2) I want (need) a new reg. and think my present one will be just fine on a pony. (It's only 6 months old).
3) The wife likes the idea of a seperate air supply.
4) More and more people are using them on dives deeper than 80 feet (mostly instructors and DM's so they can hand it off if they need to.
5) And more is better, right.
As for doubling up the tanks, I just bought two PST E8-130's today and don't need that much air redundancy yet.
Do I think I'll NEED a pony? I pray I wont need it, But in the last few months I've seen some bad mistakes from other divers using rental equipment and feel better knowing I could hand a pony off to them and escort them to the surface and continue my dive with all my air if I wanted to.

 

[lamont]

if you work out the gas calculations, at a 1.0 SAC rate (and if we're dealing with n00bie divers on rental gear this might not be conservative enough), doing 30 fpm ascent and 3 mins @ 20' (or 1 @ 30, 1 @ 20, 1 @ 10), a 13 cu ft tank will only get you up from about 70 fsw. a 19 cf pony would be much better for deep dives in the 80-110 fsw range.

 

[doole]

I dive with a bunch of photographers who get focused (pun intended) on the right shot and wouldn't know if there was a problem with the buddy half the time.

I think I'd prefer the doubles/isolator manifold route, if it was practical.

That's a major mediocher buddy to be diving with.

 

[John C. Ratliff]

Okay, I've been reading all the way through this long thread, and have a few comments. Mike F. was correct in that for recreational diving, there is no need for a pony; an octopus will work fine. For years we dove with a single hose regulator (and before that, a double hose regulator) that had only one mouthpiece. We shared air with a technique (now pretty much dismissed) called "buddy breathing" if we needed to (in 40 years, I've never needed to). I dive both singles and doubles (single 72s and 80 AL, double 50s and 42s). My doubles have different manifolds (single outlet for my twin 50s, double isolation for my double 42s). I sometimes dive a double hose reg with a single hose backup (on the double 42s). I usually dive solo, and shallow (less than 60 feet).

Saying that, and reading over this discussion, I still get the feeling that there is a basic lack of water skills, and people who talk about this redundancy are becoming equipment dependent, rather than skills dependent. A competant diver should be able to do a free swimming ascent without air from considerable depth. If you can do it from 30 feet, you can do it from 60 feet; if you can do it from 60 feet, you can do it from 100 feet; all you lack is the confidence to do it, as the air you need is in your lungs already (remember Boyle's Law?). Didn't we all swim underwater the length of a 20 yard pool in basic scuba class? That's 60 feet, and it was done for a purpose. If you can do it horizontally, you can surely do it vertically with three times the gas in your lungs at depth as on the surface.

So what's the big deal about redundancy? What it is has to do with all the tech divers coming out now and telling us how we should recreationally dive. So what is the tech diver's paranoia about redundancy? Well, it is simple. They simply cannot surface, because they are decompression diving. To surface is to die. Someone above mentioned that a diver can never carry too much air. That simply is not true. A diver can have too much, get distracted, and turn a planned no-decompression dive into a decompression dive. If the diver does that, he or she cannot simply surface in an emergency. You must decompress, as there is no alternative for the tech diver. Why is there no alternative? Because they left something out in their training. What was that? Let me explain by quoting Walter Starck, a very well-known marine biologist:

...It is interesting to note that sports divers have a high incidence of permanent damage from the bends, whereas military divers, who suffer considerably more attacks, have a much lower incidence of disability. The reason is that military divers almost always have ready access to a decompression chamber, and sports divers do not. If a sports diver is hit, he is usually taken by boat or car, or both, on an hours-long journey to a hospital, where people ask slow questions about insurance and financial situations before they will ever admit him. So it acn be considerable time before the victim gets into a chamber; by then permanent nerve damage may have been done. The key to success in decompression treatment isto get the person under pressure immediately, to squeeze the bubble of nitrogen back to a size where it can no longer block a blood vessel. Decompression in the water, whece the problem started, is possibel as a last-ditch measure, but it frequently makes a bad situation worse. Another dive adds to thebottom time and usually cannot last long enough to do any good. Also, the most effective treatment involves breathing pure oxygen. I just can'tsay too much in favor of having a chamber right on hand. The decompression meters and tables that divers use are helpful, but even when they are properly followed, it is still possibel to get the bends. The tables are based only on mathematical abstractions and do not represent what is actually happening within the individual human body. Starck, Walter, The Blue Reef, A Report from beneath the Sea, Told by Alan Anderson, Jr., Alan Landsburg Productions, Inc., 1978, pg. 208

He was saying this just after telling of a bends hit his wife suffered during their research on Enewetak Atoll in the Pacific, and his successful treatment of her in the recompression chamber he had installed on their research vessel, El Territo.

I have made hundreds of dives without any redundancy. Fire fighters fight fires without redundancy. Workers enter confined spaces without redundancy. So why are tech divers so hung up on redundancy? Because they simply do not have an alternative (have I mentioned that before?). They dive deep and stay long (see the post above where the diver mentions needing more air so he can stay at 100 feet for 30-40 minutes--my dive tables from the 1970s say 25 minutes for no-decompression diving on air. And they dive in overhead environments.

So I have a question for the tech divers posting on this thread--why don't you demand that all dive operators who allow decompression diving off their boats have a recompression chamber on-board? It would save a lot of lives if this were a requirement, and perhaps several books would not now be in print which give diving a very bad name in the public's eye(The Last Dive by Bernie Chowdhury comes to mind).

My comment is that the dive operators who are requiring at least pony bottles are probably trying to avoid lawsuits, and also avoid putting chambers on their boats. If someone dies, they can say "But we required redundant dive systems."

So, I would like to know...why no recompression chambers available for tech divers?

SeaRat

 

[lamont]

Someone above mentioned that a diver can never carry too much air. That simply is not true. A diver can have too much, get distracted, and turn a planned no-decompression dive into a decompression dive.

The problem there is the diver's lack of situational awareness, not the extra air.

So what's the big deal about redundancy? What it is has to do with all the tech divers coming out now and telling us how we should recreationally dive. So what is the tech diver's paranoia about redundancy? Well, it is simple.

I don't think its as simple as you think it is. If you're diving solo (within recreational limits) and your first stage fails so that you lose your gas, you will definitely miss your stop, and if you try to surface slowly to minimize the risk of DCS or embolism you may not have any gas to inflate and get positive. You can orally inflate, but add some rough seas or anything else going wrong and the situation can get nasty. My own risk assessment is that situation is unnacceptable risk and is worth carry some redundancy to prevent.

So, I disagree that its only tech divers that need redundancy. IMO, everyone needs either doubles, a pony bottle, or an attentive buddy. And my opinion has nothing to do with tech diving or decompression, and is based entirely on the failure possibilities of purely recreational dive gear.

 

[Soggy]

Good luck swimming back to an anchor line solo with no redundancy....I sure don't want to be doing a free swimming ascent from 130 ft away from the boat with no lift bag.

 

[doole]

IMO, everyone needs either doubles, a pony bottle, or an attentive buddy. And my opinion has nothing to do with tech diving or decompression, and is based entirely on the failure possibilities of purely recreational dive gear.

Definitely agreed. The twitchy word here being, 'attentive', IMO.

If you're diving solo (within recreational limits) and your first stage fails so that you lose your gas, you will definitely miss your stop, and if you try to surface slowly to minimize the risk of DCS or embolism you may not have any gas to inflate and get positive.

What kind of failure can cause an immediate out-of-air situation, and how often does it occur? Not trying to make any particular point; I really am asking. I once saw a fairly spectacular yoke valve O-ring failure, but fairly early in the dive and the diver still had time to do a reasonable safety stop. In 12 years of diving, that's all I ever saw.

I don't think I've ever heard of another OOA event that wasn't caused by gas mismanagement. (Talking rec diving here, of course.) And if they're gonna mismanage their gas, who can say they'll be able to use their redundant gear properly? Or know which way to go to find the surface?

Anyone know are there any stats on OOA's not caused by gas mismanagement?

 

[Web Monkey]

A competant diver should be able to do a free swimming ascent without air from considerable depth. If you can do it from 30 feet, you can do it from 60 feet; if you can do it from 60 feet, you can do it from 100 feet; all you lack is the confidence to do it, as the air you need is in your lungs already (remember Boyle's Law?).

First, accidentally running out of air is different from a planned drill, since you don't have time to take another breath and prepare for being out of air. People notice they're out of air when they've already exhaled and there's no (or minimal) inhale, so they're unlikely to have a nice lung full of fresh air.

In the event of a failure with a missing buddy, I could probably make a free ascent from 100 feet or maybe even 130, however the chances of being severly injured are much greater than if I made a nice slow ascent, including a deep stop at 50 and a 3 minute stop at 15.

So what's the big deal about redundancy? What it is has to do with all the tech divers coming out now and telling us how we should recreationally dive. So what is the tech diver's paranoia about redundancy? Well, it is simple. They simply cannot surface, because they are decompression diving.

All dives are decompression dives. The dives within the NDL are deco dives where the time required to do a nice slow ascent is equal or greater than the time required to decompress enough that most people won't get injured.

A rapid free ascent from 130 may get you to the surface before you drown, but will also get you a ride to the chamber, assuming one is nearby and available.

There's nothing wrong with redundant equipment on a rec dive. However it is voluntary. If you don't want it, don't bring any.

Terry

 

[Web Monkey]

I don't think I've ever heard of another OOA event that wasn't caused by gas mismanagement. (Talking rec diving here, of course.)

The cause doesn't really matter. Maybe the diver was narced and was talking to the pretty fish, maybe the gauge stuck and read 1000 PSI when there's no air left. Doesn't really matter, since OOA does happen. This is like arguing against air bags in cars since they're only used during collisions.

And if they're gonna mismanage their gas, who can say they'll be able to use their redundant gear properly? Or know which way to go to find the surface?

At least it's a chance. If there's no extra gas, they absolutely won't be able to use it.