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quarkuud
04-21-2008, 02:08
I've done negative buoyancy entries on two different dive boats. The first one suggested that we hold down the manual inflate button and actually suck the air out of the BC to make sure we had it all out. The other said never to do that because of possible bacteria inside the BC.

What do you guys think? Assuming the BC is personal gear and kept clean and disinfected regularly, of course. Would you suck air out of your BC?

navyhmc
04-21-2008, 02:49
Sucking air out of my BC has never been a planned method of deflation for me. More so because why should I do that when I can let water pressure accomplish this or just squeeze the dickens out of it. But, if it works for you, go for it.

mitsuguy
04-21-2008, 07:14
Sucking air out of my BC has never been a planned method of deflation for me. More so because why should I do that when I can let water pressure accomplish this or just squeeze the dickens out of it. But, if it works for you, go for it.

water pressure does a very good job at pushing air out of a bc... I couldn't imagine you being able to suck more out than water pressure will push out...

oddbod
04-21-2008, 07:38
I've done negative buoyancy entries on two different dive boats. The first one suggested that we hold down the manual inflate button and actually suck the air out of the BC to make sure we had it all out. The other said never to do that because of possible bacteria inside the BC.

What do you guys think? Assuming the BC is personal gear and kept clean and disinfected regularly, of course. Would you suck air out of your BC?

Extremely hazardous to your health, the bugs inside could be deadly, they like moist, dark places.:smiley11: I wouldn't trust trying to disinfect it. There was a story around years ago about people dying from using air in their BC to increase dive time??

MicahEW
04-21-2008, 09:32
I have been told to NEVER suck air out of the BC for bacteria issues. Its about as clean as inhaling a persons methane from the source.

Bigg_Budd
04-21-2008, 09:48
Its about as clean as inhaling a persons methane from the source.

That's friggin' funny dude. Bravo!

terrillja
04-21-2008, 09:51
There was a story around years ago about people dying from using air in their BC to increase dive time??
Increase dive time by what, 30 seconds? There isn't too much air in your BC, and there shouldn't be much at all if you are properly weighted.

cummings66
04-21-2008, 09:53
I personally don't think it'd kill you by inhaling the bacteria, but I do think that what was said in the past was people died doing it because they didn't get enough O2 to live and passed out, then drowned.

I don't think you need to suck the air out to do a negative entry, you're heavy on the first dive anyhow, just don't put air in it and you'll be negative.

No Misses
04-21-2008, 10:08
I do negative entries on most dives (planned). I just hold the rear dump open and "wrap" my wing around the tank. You can do the same thing with a jacket style BC, by holding open the dump valve and squeezing the bladder.

BTW: If you really want to suck, knock yourself out. I wont tell. :smilie39:

CompuDude
04-21-2008, 12:41
It's unlikely to kill you, but I would reserve sucking the air out of the BC for true emergencies, due to the bacterial risk. It's better than drowning, but should not be part of a regular dive plan. Not worth the risk.

ReefHound
04-21-2008, 12:54
There was a story around years ago about people dying from using air in their BC to increase dive time??
Increase dive time by what, 30 seconds? There isn't too much air in your BC, and there shouldn't be much at all if you are properly weighted.

If this actually happened, I suspect they were using their BC as a "rebreather" and succumbed to hypoxia or CO2 poisoning.

scubasamurai
04-21-2008, 13:02
yuck for me, even though i throughly clean the bc and even let it soak for a day or too it never seems to get that salt or lake water out and you never know what bacteria can be in there. me i squeeze the heck out of it and if i can't get out the air let the pressure do it.
if you do suck the air out let us know if you get any weird infections of the lung
just kidding

ReefHound
04-21-2008, 13:14
yuck for me, even though i throughly clean the bc and even let it soak for a day or too it never seems to get that salt or lake water out and you never know what bacteria can be in there.

The same bacteria living in your second stage which you breathe out of for an hour on a dive.

ChrisA
04-21-2008, 13:22
I've done negative buoyancy entries on two different dive boats. The first one suggested that we hold down the manual inflate button and actually suck the air out of the BC to make sure we had it all out. The other said never to do that because of possible bacteria inside the BC.

What do you guys think? Assuming the BC is personal gear and kept clean and disinfected regularly, of course. Would you suck air out of your BC?

Unles you plan on sucking air from the BC on every dive don't do it durring the test. Do the test using the same procedure as when you dive. I don't think anyone advises to suck air from a BC on every dive, not only possible bacteria but it is just plain ineffective. Water pressure does a good enough job. If you are vertical in the water and hold the inflater tube up. there is enough pressure on the BC bladder to force air out. The extra foot you gain by holding the tube up is about as much as you would suck using lung power. and I'd not really want to know what's growing inside a BC.

One more thing. That weight check at the surfface will only get you "close". To be 100% fine tuned you should do the check at 15 feet with 500 or 600 PSI in the tank. see if you can hover with no air in the BC. Bring a few 1 poind weight to hand off with a buddy. Just hold them in your hands, thumbs tucked in waistband the ankles locked and remain motionless at 15 feet. when you can do that you are weighted perfectly

ChrisA
04-21-2008, 13:30
yuck for me, even though i throughly clean the bc and even let it soak for a day or too it never seems to get that salt or lake water out and you never know what bacteria can be in there.

The same bacteria living in your second stage which you breathe out of for an hour on a dive.

That's not quite true. The second stage gets rinsed out after every dive. The parts that can't be rinsed (inside the low presure hose and upstream of the demand valve) are never in contact with ocean water. So all the ocean water is rinced out after ever dive. But more importently is that these parts of the second stage eventually dry out by exposure to air while in storage. The inside of the BC on the other hand never really can dry out. When you hand is off the dump valve the BC is closed up

The bateria they worry about is not what is in the water you are diving in but what grew in the BC while you were not diving

ChrisA
04-21-2008, 13:39
There was a story around years ago about people dying from using air in their BC to increase dive time??
Increase dive time by what, 30 seconds? There isn't too much air in your BC, and there shouldn't be much at all if you are properly weighted.

If this actually happened, I suspect they were using their BC as a "rebreather" and succumbed to hypoxia or CO2 poisoning.

Let's say you really did want to extend you dive time by storing air in the BC. How much could you store in there. Water is about 64 pounds per cubic foot. So for every cu ft you "store" extra in the BC you'd need to add 64 poinds of lead to your weight belt. Not many BCs even have that much capasity. Most top out at about 32 pounds lift or 0.5 cu ft volume. Even blown up full at the surfave the BC has at most .5 cu ft. Not enough to extend a dive for very long.

ReefHound
04-21-2008, 13:41
A cool freshwater rinse does not kill bacteria. There's a reason you wash your hands with *soap* and water, and the dishwasher uses 180 degree hot water.

ReefHound
04-21-2008, 13:45
[quote=ReefHound;160557]Let's say you really did want to extend you dive time by storing air in the BC. How much could you store in there. Water is about 64 pounds per cubic foot. So for every cu ft you "store" extra in the BC you'd need to add 64 poinds of lead to your weight belt. Not many BCs even have that much capasity. Most top out at about 32 pounds lift or 0.5 cu ft volume. Even blown up full at the surfave the BC has at most .5 cu ft. Not enough to extend a dive for very long.

You don't get it. You wouldn't "store" air in the BC as if it were a tank. You would use it as a "rebreather". Inhale from reg, exhale into BC, inhale from BC, exhale into water. You only use part of the oxygen in a breath, but the problem is if you rebreathe air 2 or 3 times you will be under the 16% minimum required, and rebreathing even once is drastically elevating your CO2 exposure.

ReefHound
04-21-2008, 13:54
Here are some numbers that demonstrate why rebreathing your air even once is very bad. From wikipedia:

"A person's exhaled breath is approximately 4.5% carbon dioxide by volume.
It is dangerous when inhaled in high concentrations (greater than 5% by volume, or 50,000 ppm)."

"People who breathe 50,000 for more than half an hour show signs of acute hypercapnia (http://en.wikipedia.org/wiki/Hypercapnia), while breathing 70,000 – 100,000 can produce unconsciousness in only a few minutes."

Carbon dioxide - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Carbon_dioxide)

terrillja
04-21-2008, 14:14
Here are some numbers that demonstrate why rebreathing your air even once is very bad. From wikipedia:

"A person's exhaled breath is approximately 4.5% carbon dioxide by volume.
It is dangerous when inhaled in high concentrations (greater than 5% by volume, or 50,000 ppm)."

"People who breathe 50,000 for more than half an hour show signs of acute hypercapnia (http://en.wikipedia.org/wiki/Hypercapnia), while breathing 70,000 100,000 can produce unconsciousness in only a few minutes."

Carbon dioxide - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Carbon_dioxide)
So who signed up for that study? Guessing the military did that study...

ScottZeagle
04-21-2008, 14:18
I'll admit it...I have sucked the air out of my BC bladder before rolling into the water. Often, it is the first guy who gets to the bottom who has the best opportunity to shoot the best fish...

And, to quote Eddie Vedder...."I'm still alive."

YMMV.

reactive
04-21-2008, 14:25
I dive in Lake Ponchatrain in New Orleans for research purposes and I get that nasty water in my mouth every time I dive there. Especially nasty since they opened the spillway and all the mississippi river water is flooding the lake. That's far nastier than anything that gets in my BC. I still don't think I'd suck the air out of it though.

fisheater
04-21-2008, 17:24
I'll admit it...I have sucked the air out of my BC bladder before rolling into the water. Often, it is the first guy who gets to the bottom who has the best opportunity to shoot the best fish...

And, to quote Eddie Vedder...."I'm still alive."

YMMV.

Don't let your lawyers hear you say that!

Your own BC Manual says "though shall not" breath from your BCs. Actually, it says:


NEVER breathe from the bladder assembly. The bladder assembly was not designed as an auxiliary air source and may contain harmful contaminants, which if inhaled, may cause injury or death.

reactive
04-21-2008, 17:26
I'll admit it...I have sucked the air out of my BC bladder before rolling into the water. Often, it is the first guy who gets to the bottom who has the best opportunity to shoot the best fish...

And, to quote Eddie Vedder...."I'm still alive."

YMMV.

Don't let your lawyers hear you say that!

Your own BC Manual says "though shall not" breath from your BCs. Actually, it says:


NEVER breathe from the bladder assembly. The bladder assembly was not designed as an auxiliary air source and may contain harmful contaminants, which if inhaled, may cause injury or death.





Ouch Scott! You want some aloe? That was a pretty bad BURN!

fisheater
04-21-2008, 18:02
I'll admit it...I have sucked the air out of my BC bladder before rolling into the water. Often, it is the first guy who gets to the bottom who has the best opportunity to shoot the best fish...

And, to quote Eddie Vedder...."I'm still alive."

YMMV.

Don't let your lawyers hear you say that!

Your own BC Manual says "though shall not" breath from your BCs. Actually, it says:


NEVER breathe from the bladder assembly. The bladder assembly was not designed as an auxiliary air source and may contain harmful contaminants, which if inhaled, may cause injury or death.





Ouch Scott! You want some aloe? That was a pretty bad BURN!

It was a FRIENDLY burn, from a very satisfied customer. (Brigade - with trim pockets and yellow "thingies" -, Tech bladder, Envoy Deluxe, Octo-Z, Ranger snorkel, Diver Toolkit)

Sounder
04-21-2008, 18:16
I wouldn't ever suck the air out unless it meant that or drowning. Too much risk of crapola... and I rinse, disinfect, and dry (as best I can) the inside of my wing all the time.

You shouldn't have any trapped air in your BC large enough to slow you down beyond what you can easily vented.

Uugh... sucking air from my wing makes me sick just thinking of it!! :smiley11:

Sounder
04-21-2008, 18:17
I'll admit it...I have sucked the air out of my BC bladder before rolling into the water. Often, it is the first guy who gets to the bottom who has the best opportunity to shoot the best fish...

And, to quote Eddie Vedder...."I'm still alive."

YMMV.

Don't let your lawyers hear you say that!

Your own BC Manual says "though shall not" breath from your BCs. Actually, it says:


NEVER breathe from the bladder assembly. The bladder assembly was not designed as an auxiliary air source and may contain harmful contaminants, which if inhaled, may cause injury or death.




Oops!

texdiveguy
04-21-2008, 23:06
I have preformed this only once as part of some advanced technical diving self-survival skills (and it was 'optional' per the instructor to actually breath down the gas from the wing) while in this particular training dive. I opted to do it as I wanted the experience in case I actually needed to use this skill in the future. **But I don't recommend breathing off ones bc wing. Simply 'squeeze' the gas from the wing prior the entering the water if this is the method of entry you are wanting.

mobeeno
04-21-2008, 23:06
First time I have ever heard someone sucking air from the bc.

Marcus
04-21-2008, 23:29
As a medical person, I doubt very much that bacteria in your BC is a factor at all. Sucking air out of your BC doesn't make any sense, but then again, nor does bacteria. Tons of bacteria in everyday life that you could be effected by if you were/are immunocompromised. Other than that, breathing air out your BC is likely not a risk factor at all.

Sounder
04-22-2008, 10:26
As a medical person, I doubt very much that bacteria in your BC is a factor at all. Sucking air out of your BC doesn't make any sense, but then again, nor does bacteria. Tons of bacteria in everyday life that you could be effected by if you were/are immunocompromised. Other than that, breathing air out your BC is likely not a risk factor at all.

I would guess there are many diving medical professionals that would disagree. I see the wing as a perfect place for bacteria to concentrate and build.

During my undergrad chem class, we had the opportunity to culture and grow bacteria from things like the toilet seat, the door handle, the drinking fountain, etc... once we placed them in the dish, we weren't allowed to open them as the instructor didn't know what might be growing and now be present in greater numbers in the dish.

I guess my question is "why?" What is gained from doing it other than in a life threatening emergency? Why risk it at all?

ScottZeagle
04-22-2008, 12:48
I think there is some miscommunication going on here...

What the original poster asked, if I am understanding it correctly, is have you ever sucked the air out of your BC bladder before diving, so that your bladder is (for the most part) completely void of air.

Somewhere along the way, it turned into a discussion about actually breathing air from your BC bladder while underwater.

Apples and oranges.

texdiveguy
04-22-2008, 13:00
I think there is some miscommunication going on here...

What the original poster asked, if I am understanding it correctly, is have you ever sucked the air out of your BC bladder before diving, so that your bladder is (for the most part) completely void of air.

Somewhere along the way, it turned into a discussion about actually breathing air from your BC bladder while underwater.

Apples and oranges.

Scott, hang around long enough and it will probably move onto which has the worse contaminated gas in it---oval or horseshoe shaped wings....maybe even jacket bladders!

CompuDude
04-22-2008, 13:00
I think there is some miscommunication going on here...

What the original poster asked, if I am understanding it correctly, is have you ever sucked the air out of your BC bladder before diving, so that your bladder is (for the most part) completely void of air.

Somewhere along the way, it turned into a discussion about actually breathing air from your BC bladder while underwater.

Apples and oranges.

Not really. The issue of concern, with sucking the air out of your BC, is bacterial infection in the lungs due to nastiness hiding in the bladder. There's no difference in this risk whether you are sucking the air out on the surface or at depth.

At depth, when it's a choice between that and drowning, I say go for it... if that's the only air available, breathe it!

On the surface, there is no benefit that is sufficient to warrant any possible risk of lung inflection. The small extra amount you may be able to suck out is not going to help your dive very much... and the tiny amount that it may help (for the first 20 feet, after which you'll probably be adding a puff or two of air anyway?) is definitely not worth any risk.

Is it a big risk? Medical opinions differ. But unless you're regularly cleaning out the inside of your BCs/wings with anti-bacterial solution (or bleach, etc.), I'd say even the small risk is definitely not worth the dubious reward.

ScottZeagle
04-22-2008, 13:23
Is it a big risk? Medical opinions differ. But unless you're regularly cleaning out the inside of your BCs/wings with anti-bacterial solution (or bleach, etc.), I'd say even the small risk is definitely not worth the dubious reward.

Hmmmm...

Have I ever told you about the new Zeagle BX system?? It now comes standard on all Zeagle BCs and allows you to attach a garden hose to your bladder and rinse it completely!!!

Perfect for people who not only want to make sure their gear is kept freshly rinsed, but also perfect for people who may or may not want to breath, suck, or nurse from their BC bladder!!!

(Please don't try this at home, your mileage may vary, reproduction of this post without express written consent of the original poster is illegal, etc.)

Disclaimer: If you think this post is 100% serious in nature, please step away from the computer, walk around outside, and get some fresh air.

;)

ScottZeagle
04-22-2008, 13:24
Scott, hang around long enough and it will probably move onto which has the worse contaminated gas in it---oval or horseshoe shaped wings....maybe even jacket bladders!

Gotta love the internet!!!

:D

texdiveguy
04-22-2008, 13:26
Disclaimer: If you think this post is 100% serious in nature, please step away from the computer, walk around outside, and get some fresh air.

;)

The sad thing is there are to many members of the ST forum that take everything said as 100% serious---LOL

UCFKnightDiver
04-22-2008, 13:29
I have heard... If you know your going to drown if your stuck or something and all your air has run out it is better to breath from your bladder because the CO2 buildup will make you pass out rather than being concious while you drown.

Guess thats a bit hard to say but yes I have heard it and it makes sense sorta....

texdiveguy
04-22-2008, 13:31
I have heard... If you know your going to drown if your stuck or something and all your air has run out it is better to breath from your bladder because the CO2 buildup will make you pass out rather than being concious while you drown.

Guess thats a bit hard to say but yes I have heard it and it makes sense....

"Gotta love the internet!!!" ScottZeagle

EuphoriaII
04-22-2008, 13:47
I've sucked air out of the BC at home when packing for a trip to get it as compact as possible. So far no ill effects that I know of

reactive
04-23-2008, 00:38
Is it a big risk? Medical opinions differ. But unless you're regularly cleaning out the inside of your BCs/wings with anti-bacterial solution (or bleach, etc.), I'd say even the small risk is definitely not worth the dubious reward.

Hmmmm...

Have I ever told you about the new Zeagle BX system?? It now comes standard on all Zeagle BCs and allows you to attach a garden hose to your bladder and rinse it completely!!!

Perfect for people who not only want to make sure their gear is kept freshly rinsed, but also perfect for people who may or may not want to breath, suck, or nurse from their BC bladder!!!

(Please don't try this at home, your mileage may vary, reproduction of this post without express written consent of the original poster is illegal, etc.)

Disclaimer: If you think this post is 100% serious in nature, please step away from the computer, walk around outside, and get some fresh air.

;)

Well done sir. You're the only one I know that can shamelessly plug their product and get genuine laughter out of their customers!

:smiley20:

quarkuud
04-23-2008, 06:18
Several people suggested that water pressure would work.


Water pressure does a good enough job. If you are vertical in the water and hold the inflater tube up. there is enough pressure on the BC bladder to force air out.

I'm only talking about a negative buoyancy entry. In these, you go immediately under after entering the water, so you need the air out before you get in the water. These are usually done when the conditions don't favor hanging around on the surface, and I've only done them when there was too much surge. If you can't get down immediately, you will be in a bad place. I find it harder to get under in these even when I am properly weighted because my default behavior when I hit water is to kick and try to swim.

If I had a BC that trapped air I probably would be willing to suck out the air (I've been able to get it out with judicious squeezing so far). But I'm a pretty big believer in keeping my immune system busy, so your mileage may definitely vary. And everyone's opinions here have made me more determined to try harder on getting the air out another way.

And I'll stop here before I use any more double entendres. Thanks, everyone.

bates28
04-26-2008, 07:17
Yeah i would bet that would make you sick

Flatliner
04-26-2008, 07:38
Disclaimer: If you think this post is 100% serious in nature, please step away from the computer, walk around outside, and get some fresh air.

;)

The sad thing is there are to many members of the ST forum that take everything said as 100% serious---LOL

You guys aren't serious...

Dang it, I was thinking I could get a bigger wing and an O2 bottle instead of a re-breather...

Flatliner
04-26-2008, 07:40
I've sucked air out of the BC at home when packing for a trip to get it as compact as possible. So far no ill effects that I know of

I actually PUT a little air in my wing when packing for a trip to add a layer of protection from the luggage apes.

huvrr
05-13-2008, 11:37
can't believe I actually read all these posts. maybe I should get a job

wolfen42
05-13-2008, 11:49
Disclaimer: If you think this post is 100% serious in nature, please step away from the computer, walk around outside, and get some fresh air.

;)

The sad thing is there are to many members of the ST forum that take everything said as 100% serious---LOL

You guys aren't serious...

Dang it, I was thinking I could get a bigger wing and an O2 bottle instead of a re-breather...

In OUR OW training they filled all OUR BCD's with pure O2 and told us to breathe off them on our deco stops on our 150' initial dive. Is this standard PADI procedure?

Zyxistal
05-13-2008, 12:05
YOU ARE GOING TO DIE!!!!!!

Sorry I couldn't resist it.

elijahb
05-14-2008, 19:38
I would reserve sucking the air out of the BC for true emergencies
Some people I know who dive solo have told me stories about running out of air. They would breath the air out of there bc to get them to the surface I guess it gives you a couple more breaths if you really need it. When you breath the air out of your bc you would lose buoyancy so if you are out of air than you better drop your weights before you empty your bc into your lungs

Grin
05-15-2008, 09:39
I do negative entries on most dives (planned). I just hold the rear dump open and "wrap" my wing around the tank. You can do the same thing with a jacket style BC, by holding open the dump valve and squeezing the bladder.

BTW: If you really want to suck, knock yourself out. I wont tell. :smilie39:

Red flag, Busted! I've seen you suck your bladder empty a few times. I was going to post how I've seen a few(you being the person I'm thinking about) do it. If the currents ripping and your trying to hit a wreck, it makes good sence to not be screwing around floating on the surface after splashing when the capt says "DIVE". I have often thought this, as I never have been smart enough to suck the bladder empty. I always find myself having to screw around for a few seconds after splashing and then remembering this technique I never remember until it's too late. Normally it is a "who cares" / "what's the big deal about a extra few seconds" situation. But I've seen it done and thought it was a decent idea for that siutuation.

doczerothree
05-15-2008, 09:51
Only time I would suck gas from my BC is if I was OOA.