Pony bottle assisted snorkeling/diving

[Van Isle]

to whit

4. Yes i do see the dangers of holding your breath on an ascent. Of course i do. At no stage has any one in the lead advocated this action. Except Van isle. Mmmmmm....nuff said. We've covered the derisory condescension angle already. I would add that a correctly trained diver would not inadvertently, accidentally or instinctively hold his breath, ascent or not.

And at what rate, exactly, would a trained SCUBA-breathhold diver release their breath on ascent, and how would they judge that rate and its perfection of execution to ensure they are avoiding an embolism?

6. I don't see the likelihood of forming health threatening bubbles with the profiles i've suggested, no. Do you? Am i wrong? Wouldn't it be nice to be able to get answers to questions like this from learned professionals, in a friendly, conversational fashion? may be there's a web site?

Yes, I do see the likelihood of forming health-threatening bubbles. And I've seen no tested, or even properly theorized, method of understanding their formation or dissipation over randomized and continuously variable pressure gradients. Not to mention CO2 retention possibilities, ignored shallow water blackout potential, and a host of other potential problems a n00b like me cannot even comprehend. But to your age and experience I will acquiesce.

 

[RalphinOrmond]

Just a word of support for at least part of Dantheengineer's point, as I understand it. There did seem to be the idea by some others that the OP (and/or anyone reading the thread) is capable of doing things with a tank that would present dangers beyond his expectation. As the OP is an experienced diver, a respectful reply from people who are more knowledgeable seems like an appropriate and good thing. Sarcasm and rudeness are not helpful. In this respect, I think Dantheengineer's point is well taken and the responses in denial of this are also not helpful. But then there is the issue that every post must be speaking to a hypothetical reader who knows nothing about anything and is entirely capable of strapping on a pony bottle and doing deep dives or bounce dives, or maybe filling it with nitrox, or carbon dioxide, or dirt. Any poster who forgets for a moment the foolish and reckless in the world is thought to be highly irresponsible. In my opinion, anyone who straps on a bottle and goes diving without having been trained by professionals really should know better and does not need more than a simple warning.

 

[ditch-diver]

I do not think people are being rude here.., do not confuse directness with rudeness. Going with the old saying "You can't suck and blow at the same time" you are either snorkelling or diving, but not both. My interpretation is that is what those opposed are trying to say.

I guess if looking for solid advice from people here, lets be a little more specific. What do you want the pony bottle for??

Is it for safety so that you can extend your breath hold time on the bottom by not needing breath hold time for ascent and when you need to breathe, pop the reg in and do a controlled ascent at the proper rate and avoid the risk of shallow water black-out?

Or are you looking at extending dive time..., deep breath on the surface, swim down ..., swim around pop the reg in take a couple deep breaths and then hold your breath again to extend your bottom time?

Two very real possibilites, two very different scenario's. What are you looking for with a pony bottle? That is the question. Well, that and "To be or not to be..."

 

[Cave Diver]

1. You make my point wonderfully (one, at least ) from the off set. Why are you telling me what i advocate? Why don't you try to understand what the other half of a conversation IS saying? (Or is it just poor choice of syntax?)

No. I didn't tell you what you advocate. I asked a question. Perhaps I'm not the only participant in this thread that needs to work on understanding.

2. Actually, i am saying precisely that. For the same reasons one would employ Positive Reinforcement in the instruction of those wishing to partake of the "potentially risky behavior" intrinsic to scuba.

So my understanding was correct but you're finding fault with my attempt to clarify it. It appears that you're just looking for a reason to argue.

6. I don't see the likelihood of forming health threatening bubbles with the profiles i've suggested, no. Do you? Am i wrong? Wouldn't it be nice to be able to get answers to questions like this from learned professionals, in a friendly, conversational fashion? may be there's a web site?

It's funny that you don't appreciate the use of a bit of sarcasm from others but don't seem to mind employing it yourself.

3. "If he learns there are risks that he hadn't thought of and......." How's he or anyone going to learn anything if the only answers are dismissive and sarcastic to the extent that IF he was a newbie (actually a PADI rescue diver from profile) he may even take seriously. Given the advice comes from a very experienced and massively advanced diver like yourself. (Cave/ CCR etc) "What could possibly go wrong?"
4. Yes i do see the dangers of holding your breath on an ascent. Of course i do. At no stage has any one in the lead advocated this action. Except Van isle. Mmmmmm....nuff said. We've covered the derisory condescension angle already. I would add that a correctly trained diver would not inadvertently, accidentally or instinctively hold his breath, ascent or not.
5. I'm sure the both the OP and i are trained and familiar with the practicalities of breathing compressed air at depth. To the extend that we both claim certification anyway. Not easy to prove online unless Scubaboard starts checking c card numbers before issuing id's.
6. I don't see the likelihood of forming health threatening bubbles with the profiles i've suggested, no. Do you? Am i wrong? Wouldn't it be nice to be able to get answers to questions like this from learned professionals, in a friendly, conversational fashion? may be there's a web site?
(for information:-I know many spear fishermen over here that dive similar profiles, (tanks and/or hooka) are they all risking their health?)
7. I see risks. I enjoy managing them. That's diving for you. When i don't see risks and i recognize the possibility of danger in a situation i ask a professional. S'kinda why i'm here........

8. As an aside, whilst i concede the point that non divers may be reading these posts and should be protected from unforeseen and misunderstood danger (having foolishly only just noticed that this lead is in the snorkeling forum), i'd ask that it be moved to a more advanced forum in the interest of their protection.
The minimum number of dives for any of the posters is 25+ (except Ralphin. but the content of his post affords him due credibility) so it might be a better place for it.

The problem with your "ask a professional" premise, is that when it comes to diving phsyiology, the answer is "They just don't know." NDL's are based on a bunch of theory and guesswork and they don't universally apply to every person on every day. What used to be perfectly acceptable behavior several years ago is deemed "risky" today.

To address some of the other points brought up in this thread, I'll reference another message board: Bends report - Spearboard Spearfishing Community

Don't be stupid. A novice freediver from my workplace thought he'd do as the Tahitians while in Tahiti. They have 20-30 foot snuba hoses hanging down and they "breathe-up" at 30 feet. Then, they spit out the regulator and dive down to 60-70 feet and come back to the regulator. Surprise, surprise, he went totally deaf in one of his ears. He assumed he got water in his ear or possibly perfed his drum. He asked me about this when he got back to work. Now realize this guy is a physician (and one of the smartest I know), yet he never thought about the bends. Well, he got bent alright...and paid the price. He's lucky he didn't stroke something more vital! He's had only very minor recovery and will be essentially deaf in that ear, all for a measly 30 feet (10 seconds down and 10 seconds up - big deal).

Be safe out there. Common sense tells you that what he was doing was not safe, but he also thought you can't get bent freediving. WRONG! Do proper surface intervals. Competitive freedivers never(?) get bent because of their long surface intervals, but spearos do all the time - and it's usually devastating Type 1 (neuro damage), rather than Type 2 (joint aches and pains, etc.). The obvious - don't do as the Romans, just because you are in Rome ---They probably don't have a freakin clue! Dive safe...dive another day. PEace out.

I'll address a secondary issue on the next post.

 

[Cave Diver]

A few points:

1) I'm not a doctor and I did not stay at a Holiday Inn last night.
2) I'm referencing this WKPP posting because it is a good source of information, not as a DIR/anti-DIR way of doing things.

Why we Don't bounce dive after diving in the WKPP By George Irvine


Guys read this for once. WHY WE DO NOT BOUNCE DIVE AFTER DIVING IN THE WKPP It is ok to offgas from the tissues into the blood stream in bubble form in the later steps of decompression as it is a more efficient, faster way of getting rid of the remaining gas ( by reduced pressure ) than by elevated oxygen alone ( which starts taking exponentially more time with greater risk) . However, this depends on having a good lung filter and no shunts. All of you have been PFO tested if you are diving with us. The correct way to ascend from the last stop is one foot per minute for the bigger dives.

The greatest potential for offgassing in bubble form is when the pressure is totally removed back to one ATA out of the water. Now you get a real shower of bubbles , relative to what was happening in the water. A good , clean deco with the foot per minute ascent reduces this dramatically . In MOST people, the greatest bubbling occurs out of the water and continues for up to four hours, not even peaking for a couple of hours. In a well vascularized, fit person like me, it is over with in 30 minutes. Don't bet on that with most of you. In ALL people, the bubbles continue to grow in size after the pressure is off. They accumulate like gas into themselves from the surrounding blood or tissues ( if there are bubbles in the tissues or injury sites ) and they grow bigger. This is why you feel pain later rather than earlier if the bubbles are in joints or tissues - they get bigger before they begin to shrink. This is why what starts out as micro bubbles can get by the lungs and grow and get lodged downstream, and you get neurological symptoms later.
Now here is the important part. If you understand everything I have said above, then you know that bouncing to 20 feet or whatever to pick up a bottle and immediately returning to the surface is the like giving yourself a home-made PFO: the bubbles in the venous side compress enough to get past the lungs and then will reexpand on the arterial side and lodge in the worst places , the spine and brain blood supplies. You do not want this. If you dive after dive, stay down and let everything reset. Get the bubbles all compressed, and then deco out and ascend accordingly. I do not want support divers diving support within four hours of doing a real dive or deep support. This works out fine, since we have support activities lasting up to 18 to 24 hours and need to rotate everyone. Let me assure you that we have found this out the hard way in the past. Parker used to get hot as hell when it would happen. In those days we had "volunteers", and they would all get bent diving to 20 feet to pick up bottles. We have also seen some severe cases of this where dives were done away from the project with no support, and the players went back for bottles later and got hammered. Don't do it. Also, obviously, do not freedive after a dive. When you want to freedive, do that first and then go scuba diving. Any questions from WKPP guys?

The conclusions reached here came from extensive trials and doppler research after numerous dives.

My OW instructor taught me to never do bounce diving and to always do a safety stop, even within NDL's.

My take on all of this is that anytime you breathe compressed air, you are absorbing nitrogen into your tissues. The issue has been raised before of the dangers of instructors possibily suffering DCS from doing repeated CESA drills with OW students from as shallow as 30'. It's not hard for me to imagine that even shallow freedives combined with SCUBA could cause microbubble seeds and lead to potential for neurological DCS or embolisms. You may have more experience and medical training than I do and have a different conclusion.

Combining freediving and SCUBA invites someone to go just a bit deeper and perhaps stay just a bit longer than they would on breathhold alone. Free divers tend to go down fast and don't adhere to a 60 fpm ascent rate and they don't do a 3 minute safety stop.

When you put these two sports together, which training is going to win out and become automatic? Slow ascents? Safety stops? Straight down then back up?

I'm not saying that it can't be done safely. I'm advocating that it will most likely end up as a risky activity, such as bounce diving, with potentially dangerous consequences. I'm all for people pursuing potentially dangerous activites. But they should understand what the risks are and make sure it falls into an acceptable level before they undertake it, not after something goes terribly wrong.

If divers are as well trained as your previous post infers, then my previous mention of bounce diving should be all the warning they need. If they do pursue this, I would hope they would look at the dangers and "rules" for both diving and free diving and take both into account when planning their dives.

 

[ScubaSteve]

What have I learned from this thread??? I have learned that there will ALWAYS be someone willing to fight for the other side no matter what that side says. There have been answers clearly indicating why this is a bad idea (in simple terms). What seems to be the problem. The OP did not make ANY mention AT ALL that they knew or understood anything about the possible dangers involved....and I learned long ago to not assume that the information contained in a profile is accurate so....not everybody recognizes every poster on SB so it is not safe to assume that anybody responding to a post will recognize the poster. Accept the answers as they are for what they are and move on. If you do not like the answers...then add the user to your ignore list. Problem solved.

I am a firm believer that many times when a person gets internet-beaten here, it is because of lack of explanation on their part or mis-information on their part. Not always, but often.

 

[Lims]

haha, right, ok..

My plan was to snorkel around, then put my pony reg in to dive down and take a photo or spend a little while longer underwater so as to see more. I will not be going deeper than 10 meters max, mostly around 5/6 meters. I'm looking into the XS Scuba Pony pack mentioned earlier.

Some good points from both sides, I expected a generally negative response.
Does anyone know the exact weight of the XS scuba pony pack? I would like to be bale to take my whole kit including the pony on public transport or walk/cycle with it on my back.

 

[Cave Diver]

haha, right, ok..

My plan was to snorkel around, then put my pony reg in to dive down and take a photo or spend a little while longer underwater so as to see more. I will not be going deeper than 10 meters max, mostly around 5/6 meters. I'm looking into the XS Scuba Pony pack mentioned earlier.

Some good points from both sides, I expected a generally negative response.
Does anyone know the exact weight of the XS scuba pony pack? I would like to be bale to take my whole kit including the pony on public transport or walk/cycle with it on my back.

IMO, if you approach it in this manner, more like a SCUBA dive, less like a free dive, by maintaining a safe ascent rate, doing a safety stop and spending a reasonable time on the surface before free diving again then it takes some of the risk out. Thanks for the clarifications.

 

[dumpsterDiver]

haha, right, ok..

My plan was to snorkel around, then put my pony reg in to dive down and take a photo or spend a little while longer underwater so as to see more. I will not be going deeper than 10 meters max, mostly around 5/6 meters. I'm looking into the XS Scuba Pony pack mentioned earlier.

.

Then you're not going to die. Never mind..

 

[TheScubaBOB]

Does anyone know the exact weight of the XS scuba pony pack? I would like to be bale to take my whole kit including the pony on public transport or walk/cycle with it on my back.

4lbs according to my bathroom scale, 4lbs in a box on the fedex truck!

I walk into the health club with it on my back and the 30cf Pony Bottle attached with 8lbs of soft weights (I used a 3mm shorty in the lap pool) in the dump pouches. It's comfortable so I think you'd be just fine.