Divers: Is there a cross between a SCUBA and a freediving setup?

[fuzzybabybunny]

Is there such a thing as a cross between a freediving and a SCUBA setup? Basically something like diving with the huge flexible fins of a freediver but with a mini, lightweight air tank that you just baby? By baby-ing the air tank I mean take a breath, hold it for as long as you can like a freediver, exhale, repeat, so that you make it last a long time? I often find that I can easily hold my breath for 1.5 minutes. If I had a mini air tank that could just provide me with something like 10 whole breaths I could remain underwater for 15 minutes.

I know absolutely nothing about diving with a tank so tell me if something wouldn't work.

 

[AndrewR]

The problem with combining the two diving methods is that you would be subject to the air changing volume as you changed depth. As I understand free diving, that's not a concern because the air will never expand beyond what your lungs can hold because the maximum volume is what it was at the surface. You would have to free dive while monitoring your depth and releasing air to compensate as you go shallower. I suppose it's doable, but it wouldn't be effortless.

There are small air tanks which are intended as "last resort" items in case your main tank or your regulator(s) fails, or a diver is stupid and runs out of air without paying attention. They're referred to as pony bottles and are good enough for a few breaths (not sure how many -- can't remember cubic inches), though I've never had personal experience with them.

 

[rgwalt]

I would think you would have problems with bouyancy control. Also, if you took a deep breath off the tank at the bottom and then decreased your depth while holding your breath, the air in your lungs could expand and cause serious problems.

R

 

[DrPizza]

Also, while you can hold your breath for 1 1/2 minutes at a time, can you do it 10 times in a row, with one breath each time?

To expand on what Andrew said, suppose while free diving, you went down to a depth of 32 feet. At that depth, you took a deep breath of air. Then, you swam back toward the surface while holding your breath. Say hello to the hospital for your pneumothorax (or something like that) - the air will double in volume on the way back up.

The "UB" in SCUBA is "underwater breathing." As soon as you take that tank of air, no matter how small it is, underwater to breath, you're doing SCUBA. Not that your idea was really that bad of an idea though. It's well worth it to take a SCUBA course.

 

[Gooberlx2]

Absolutely not. The reason freedivers can ascend and descend the way they do is because they're NOT breathing compressed air. If you take breaths at depth and then ascend like a freediver, you really risk getting bent, or worse. Most people are adept enough to not let air expand to the point of blowing out their lungs, but you can't control how gas bubbles expand in your tissues when you dive like that.

 

[fuzzybabybunny]

Hmmm... thanks for the replies guys! I've always wondered why SCUBA divers don't increase their dive times by holding their breath, say, 30 seconds at a time instead of breathing regularly.

So if I were to do this safely I'd have to basically remember to only take a small breath before going back up to the surface, or take small breaths as I'm going up to the surface? If I'm at the bottom and I take a deep breath, wouldn't that be like 2x as much oxygen as a regular breath of air, meaning I would either get lightheaded or be able to hold my breath even longer?

So basically, take a full breath to dive down. Then when I'm at the bottom, take breaths that are half as big, but contain the same amount of oxygen as one whole breath at the surface, while holding my breath. Then when I want to go up, I release the air in my lungs and slowly go up the 40 or so feet to the surface, taking small breaths if I need to?

 

[GasX]

Originally posted by: fuzzybabybunny
Hmmm... thanks for the replies guys! I've always wondered why SCUBA divers don't increase their dive times by holding their breath, say, 30 seconds at a time instead of breathing regularly.

holding your breath decreases your bottom time.

 

[daveymark]

as a rule, scuba divers should NEVER hold their breath.

 

[fuzzybabybunny]

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

When you're about to ascend, why can't you just switch back to regular breathing?

 

[rudder]

how deep are you wanting to go? They make floating compressors where you can stay under for quite a while without bulky gear. The only drawback is your tethered to the surface and typically you can not go as deep... maybe 30'.

 

[GasX]

Originally posted by: fuzzybabybunny

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

Contrary to what you might believe, holding a particular depth is not easy. You could drift up a few feet and blow out a lung - not smart at 90'

 

[fuzzybabybunny]

Originally posted by: rudder
how deep are you wanting to go? They make floating compressors where you can stay under for quite a while without bulky gear. The only drawback is your tethered to the surface and typically you can not go as deep... maybe 30'.

Wow, those are pretty cool!

http://www.browniedive.com/hooka/index.shtml

Expensive at $3K though

The electric one is cheaper, but doesn't go as deep and I won't have an external power supply

 

[swimscubasteve]

pony bottle?

that would be my guess and I am an advanced rated SCUBA diver.

 

[fuzzybabybunny]

Originally posted by: Mwilding

Originally posted by: fuzzybabybunny

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

Contrary to what you might believe, holding a particular depth is not easy. You could drift up a few feet and blow out a lung - not smart at 90'

Ah, I see. So even going up a few feet can cause the air volume to expand by a lot?

 

[daveymark]

Originally posted by: fuzzybabybunny

Originally posted by: Mwilding

Originally posted by: fuzzybabybunny

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

Contrary to what you might believe, holding a particular depth is not easy. You could drift up a few feet and blow out a lung - not smart at 90'

Ah, I see. So even going up a few feet can cause the air volume to expand by a lot?

If you're holding your breath, somewhat. you breath in and you will automatically begin to ascend slightly. the longer you hold your breath, the bigger your lungs will get if you continue to ascend.

lung overexpansion will then occur.

atmospheric pressure doubles at 33 ft. under water, triples at 66ft, etc. so you get the idea

most accidents involving lung overexpansion occur in shallower depths though. Usually what happens is the person gets anxious and starts sinking too fast, or is unfamiliar with their surroundings, or think there is a problem with their gear, so they shoot to the surface without thinking first.

 

[swimscubasteve]

Originally posted by: fuzzybabybunny

Originally posted by: Mwilding

Originally posted by: fuzzybabybunny

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

Contrary to what you might believe, holding a particular depth is not easy. You could drift up a few feet and blow out a lung - not smart at 90'

Ah, I see. So even going up a few feet can cause the air volume to expand by a lot?

No, at 90' you would have to move at least 25 feet to really notice anything.

 

[AndrewR]

Originally posted by: fuzzybabybunny

Originally posted by: Mwilding

Originally posted by: fuzzybabybunny

Originally posted by: daveymark
as a rule, scuba divers should NEVER hold their breath.

Why? If you're not ascending, what's wrong with holding your breath?

Contrary to what you might believe, holding a particular depth is not easy. You could drift up a few feet and blow out a lung - not smart at 90'

Ah, I see. So even going up a few feet can cause the air volume to expand by a lot?

It wouldn't have to expand a lot if you are taking deep breaths -- your lungs would already be filled to capacity.

Either take up SCUBA or stick to free diving.

 

[fuzzybabybunny]

I'm getting conflicting info from daveymark and swimscubasteve... I think...

ok, ok

I use a pony bottle:

Descent: Take a deep breath, descend.

Arrival: Take half deep breaths, holding breath for 45 seconds at a time or so. Nice and easy, not taking deep deep breaths or anything. When I'm diving, I don't use any weights or anything, and without kicking, if I have a half deep breath, I actually *sink*. With an absolute lungs bursting full breath I tend to float up very very slowly, probably a foot a second. Methinks with the tank and extra gear I would be more inclined to sink down instead of float on a full breath.

Ascent: Exhale, and take normal breaths until I'm at the surface. Nice and easy.

 

[swimscubasteve]

Originally posted by: fuzzybabybunny
I'm getting conflicting info from daveymark and swimscubasteve

trust the guy with "scuba" in his name.

 

[fuzzybabybunny]

previous post edited

 

[fuzzybabybunny]

Bah this sucks. I'm not quite sure what I'm thinking. Even doing what I'm stating above, I'd probably only get 10 minutes max from a pony tank. Then I gotta go up and find some way to refill it, which means more $$$ or even impossible if I don't have an air compressor or a scuba tank for refill. All that trouble for 10 minutes of "down" time doesn't quite seem worth it.

I might as well just get one of those floating air compressor thingies methinks. Too bad I live in Ohio...

 

[swimscubasteve]

what's wrong with getting scuba certified?

 

[AndrewR]

Originally posted by: swimscubasteve
what's wrong with getting scuba certified?

Uh, Steve, if she's concerned about money, going the full scuba route isn't exactly cheap. I got a great deal on my initial gear which was decidedly on the lower end (Sherwood mainly), and it still ran me $1000 without a tank.

Plus, there's a big difference between suiting up for scuba and just taking a deep breath and diving in!

 

[AUMM]

Originally posted by: fuzzybabybunny
I'm getting conflicting info from daveymark and swimscubasteve... I think...

ok, ok

I use a pony bottle:

Descent: Take a deep breath, descend.

Arrival: Take half deep breaths, holding breath for 45 seconds at a time or so. Nice and easy, not taking deep deep breaths or anything. When I'm diving, I don't use any weights or anything, and without kicking, if I have a half deep breath, I actually *sink*. With an absolute lungs bursting full breath I tend to float up very very slowly, probably a foot a second. Methinks with the tank and extra gear I would be more inclined to sink down instead of float on a full breath.

Ascent: Exhale, and take normal breaths until I'm at the surface. Nice and easy.

Your lungs aren't the only space that holds air in your body. Your tissue and body fluids etc, hold air which will expand as well. When you are scuba diving, you often have to make a safety stop at 15 ft deep for like 5 mins or so (i forget exactly) in order to make sure all your air has equalized.

 

[ajskydiver]

Please, please, please DO NOT even attempt what you've written here. The warnings you've been given here about lung over-expansion are quite real and can seriously injure you or kill you.

Yes, as swimscubasteve stated, at 90' (nearly 3 ATMs down) you have more leeway regarding a change of depth; HOWEVER, as also stated, most injuries occur in less than 33' of water because that has the largest difference in pressure - the depth you'd most likely be freediving in.

If you breathe a lungful of air at depth and hold it, you're guaranteed a serious lung over-expansion injury with even a very small change of depth.

SCUBA divers are taught an "emergency swimming ascent" that can work in approximately 30' of water...you take a lungful of air and exhale continuously all the way up while swimming to the surface (usually making an "ahhhh" sound.)

Think about that, it's got "emergency" in the title for a reason.

(No reputable dive shop would even consider selling you a pony bottle if you told them how you plan to use it.)

I've been through the Open water, Advanced open water, & Rescue courses (along with a lot of personal study and time.)

Please heed the warnings you've read here.