Recreational Pony Bottles, completely unnecessary? Why or why not?

[scubaozy]

Uncommon but fatal if you don’t mitigate the problem. A large part of diver training is for events that are uncommon but in a reasonable population happen often enough to lead to an unacceptable death rate.

What is the probability? Normally a fatality requires several conditions occurring at the same time like your buddy is not present or they did not see you or surface is far away, so, you have to multiply all probabilities that makes even smaller probability . A healthy human on land takes way more risks on their daily life than that risk. Otherwise we could not function.

 

[barth]

I am completely baffled by this. A young woman, a student in a class, decided she needed to make a quick ascent to the surface from 6 meters and evidently held her breath in violation of the first thing you are taught in scuba.

You seem to be saying that this proves that it is absolutely essential to to take 9 minutes ascending from 80 feet in an OOA situation.

I am afraid the connection between these two topics is beyond my ability to comprehend, so I will be unable to formulate an answer. In fact, I think this whole discussion has ventured well into the kind of surrealism that would have floored Kafka.

The minimum gas calculation time is 9 minutes. In the past Gue was using a different calculation. Now they are using the cat calculation.

CAT calculation for GUE Fundies

I didn't read the whole threat. But is this new? I wasn't taught this back. We were taught using the normal ascent profile for calculation, with higher SAC and additional minute for failure handling I'm not an instructor, just a recent T2 guy, so grain of salt. The point of the new CAT...

scubaboard.com

The time in minimum gas calculation is the same as the time the planned ascent requires. The minimum gas time is more conservative.

I don’t like the cat/new style calculation I prefer the old type of minimum gas calculation.

The OP is thus taking 8 minutes rather than 5 and a bit that GUE would suggest - assuming 25 to 22 takes 1 ish minute and 12 to 0 takes 4, or am I forgetting 6 minutes 6 to the surface?

So what is the procedure for an AS ascent?

From 80 feet/ 24 meter ascent with 9 meter/minute until 12 meter. Stops 1 minute @ 12,9,6 and 3 meter.

5 minutes and a bit is correct

 

[KenGordon]

What is the probability? Normally a fatality requires several conditions occurring at the same time like your buddy is not present or they did not see you or surface is far away, so, you have to multiply all probabilities that makes even smaller probability . A healthy human on land takes way more risks on their daily life than that risk. Otherwise we could not function.

That is what the mitigations do. If we didn’t train for failures and have mitigations people would die when service technicians made mistakes or they didn’t pay attention to gas use. An octopus on a buddy is a mitigation.

Look at outcomes, if people were taking bigger risks in daily life we’d see more people dying in random accidents per capita than in scuba accidents. In the U.K. about 1 in 5000 people die each year in an accident. About 10 of maybe 100k divers die In the water. While that looks like twice as many consider that those divers are spending perhaps 25 hours diving in a year so diving is probably 300 times riskier than not diving. If we subtract medical deaths (call it half) it is still 150 times more hazardous. Compared to cycling, there are millions (seven ish) cyclists in the U.K. and only 100 cycling deaths, something like 1 in 70000.

 

[scubaozy]

That is what the mitigations do. If we didn’t train for failures and have mitigations people would die when service technicians made mistakes or they didn’t pay attention to gas use. An octopus on a buddy is a mitigation.

Look at outcomes, if people were taking bigger risks in daily life we’d see more people dying in random accidents per capita than in scuba accidents. In the U.K. about 1 in 5000 people die each year in an accident. About 10 of maybe 100k divers die In the water. While that looks like twice as many consider that those divers are spending perhaps 25 hours diving in a year so diving is probably 300 times riskier than not diving. If we subtract medical deaths (call it half) it is still 150 times more hazardous. Compared to cycling, there are millions (seven ish) cyclists in the U.K. and only 100 cycling deaths, something like 1 in 70000.

This is not what I asked, I asked probability of catastrophic regulator failure. This probability is so small that I ignore it, so, I do not have a specific action or even evaluate it as a risk. AAS (pony is also an AAS) is considered minimum equipment for rec diving, as you also pointed out, it is already mitigated, so, why even bring this up?

 

[chillyinCanada]

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A ScubaBoard Staff Message...

Closed for thread cleanup.

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[chillyinCanada]

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A ScubaBoard Staff Message...

Clean up is ongoing. However, we have moved the thread to Advanced, regardless of the OP's intention.

This is still currently a Learning Zone, ergo, niceness continues to be required. That said, this Subforum and specific thread being within the greater Scubaboard Community also requires "niceness".

Refresh yourself on these Special Rules for the Advanced Subforum, the portions applying to this thread are as follows:

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[tursiops]

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A ScubaBoard Staff Message...

Clean up is ongoing. However, we have moved the thread to Advanced, regardless of the OP's intention.

This is still currently a Learning Zone, ergo, niceness continues to be required. That said, this Subforum and specific thread being within the greater Scubaboard Community also requires "niceness".

Refresh yourself on these Special Rules for the Advanced Subforum, the portions applying to this thread are as follows:

This forum is intended to be a friendly, respectful learning zone where divers of any skill level may ask questions about advanced scuba topics without fear of being attacked. Please show respect and courtesy at all times. Remember that the inquirer is looking for answers that they can understand. This is a learning zone and consequently, any off-topic, sarcastic or overly harsh responses will be removed.

Caveats:

• Commit yourself to being nice while you're here
• Not everyone will agree with you
  • That's OK and not being mean
  • It would be boring if we all believed the same thing
  • It's well within the SB ToS
• If you ask for critique and/or feedback, you should expect it.
  • You may not like the response
  • They may comment on aspects you never considered or wanted to discuss
  • It's all good and a part of the learning process.
• Never start or continue a "bicker battle"
  • If you feel someone is being abusive or overly argumentative, please ignore them and/or report the post rather than fight with them
  • Take to Private Messaging if you feel the need

PLAY NICE OR YOU MAY FIND YOUR POSTS GONE FROM THIS THREAD. FURTHER, YOU MAY FIND YOURSELF BANNED FROM THIS THREAD.

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Is this thread even necessary anymore? The OP has apologized and left.

 

[Alurpal]

I think it’s an interesting thread that shows various ways to think about what redundancy means and how to achieve it. There’s no downside to preparing for a lost/distracted/narced buddy and a catastrophic tank/first stage failure at the same time.

Personally, this thread encouraged me to understand all the different tank and regulator failure modes more deeply and ultimately led me down the road of sanitizing by bcd bladder and practicing emergency breathes from it. Through testing on land, I found that its not out of the question for me to make a cesa from 120’ after a failure that causes no air on a full exhale (60 second breath hold from full exhale followed by 2 short breaths from bcd).

My hard and fast plan is and always will be having properly maintained equipment, pre dive checklists (equipment and procedure with buddy), dive plan with rock bottom calculation, and mindful use of the buddy system.

I hope I never have to perform a real cesa, but simulating one from 120’ has proven interesting insight into what I’m capable of.

 

[tursiops]

I think it’s an interesting thread that shows various ways to think about what redundancy means and how to achieve it. There’s no downside to preparing for a lost/distracted/narced buddy and a catastrophic tank/first stage failure at the same time.

Personally, this thread encouraged me to understand all the different tank and regulator failure modes more deeply and ultimately led me down the road of sanitizing by bcd bladder and practicing emergency breathes from it. Through testing on land, I found that its not out of the question for me to make a cesa from 120’ after a failure that causes no air on a full exhale (60 second breath hold from full exhale followed by 2 short breaths from bcd).

My hard and fast plan is and always will be having properly maintained equipment, pre dive checklists (equipment and procedure with buddy), dive plan with rock bottom calculation, and mindful use of the buddy system.

I hope I never have to perform a real cesa, but simulating one from 120’ has proven interesting insight into what I’m capable of.

Yes, the thread served a purpose.

Good for you in your testing. Just be aware that in a real OOA situation, you'll be breathing harder, faster, building up CO2, and in general NOT able to duplicate a dry-land test. Be advised that breathing from a BCD has reportedly caused some nasty lung infections....which, I guess, are better than drowning.

 

[Alurpal]

All very important points! Hopefully I didn’t lead this thread down a different rabbit hole, but I thought it was important to share.