Basically I’ve got some old scuba gear and some friends at the community pool. What I want to do it hook up something so I can stay underwater for long periods. My general idea now is to hook up the regulator to a hose and lead that up the the surface. The pool has weights to keep you down, so I’ll just mosy about on the bottom.
Now, obviously I have an elementary understanding of what I’m doing, so I am looking for more information, due to the fact that I’m not interested in drowning. Will my lungs have enough suction to bring air down the hose (pool is roughly 3m deep)? I would guess I’d need some type of pump or fan, but also the depth isn’t much so I don’t know if its nessisary. Should I be worrying about the effects of water pressure?
And if this idea won’t work at all, can you tell me how to set something like this up?
You can’t breathe through a long tube if you’re far under water, because of the pressure on your chest wall. From here:
I don’t know enough about diving to tell you about how you could *make * it work, but I can guarantee you that your physiology won’t like you sitting at the bottom of a pool trying to suck air through a straw!
Generally, no, it won’t work if you go down to any significant depth. We had a discussion about this a while ago; a guy tried to fish something off the bottom of a lake by jumping off a boat and breathing through a garden hose with a weight bench weight tied around his waist. Despite some protests to the contrary, it was a Really Bad Idea.
The thing about a regulator is that it’s actually an ingenious little pressure sensitive demand valve that feeds you air pressurized to the same pressure as the surrounding water. Down at 2 atm, 2 atm of air pressure in your lungs. 3 atm depth, 3 atm of pressure in your lungs. This is why it’s of paramount importance to keep breathing while scuba diving. If you hold your breath and suddenly surface, the volume of the air in your lungs suddenly doubles, triples, or quintuples, and your lungs could conceivably burst.
So even down at three meters, your lungs are going to have a near impossible time of pulling in enough air to expand your chest cavity–they’re designed to respirate air, not pressurize it. A compressor, pump or fan that wasn’t specifically designed to feed a diver air at a certain pressure and depth would be too dangerous to use to pressurize the air, too. Your best bet for something like what you’re talking about would be a snuba, a floating scuba tank tethered to a regulator that feeds pressurized air. Make sure you always have a buddy.
You can’t draw air down more then about 2 feet due to water pressure. you have to pressurise the air in that hose to be able to breath it.
If you use the 2nd stage regulator you will need to pressurize the air even more as it is designed to opperate with a pressure of 125 psi IIRC, but could go lower if you happen to deplete the tank that much.
But, when I was a kid, my dad brought home an air compressor and a generous supply of air hose. We hooked the hose up to the compressor and I swam around the bottom of the pool with the hose bubbling into my mouth and breathing off it. No regulator, just breathing off the air pocket created in my mouth from the bubbling air hose. Worked great and was great fun.
Now I’m a certified SCUBA diver and frightened about how extraordinarily dangerous that was. Without SCUBA training an air embolism is far too likely to be playing around with in this manner. Don’t play around with compressed air without proper training - an air embolism is quite deadly and can be extremely sudden.
You know the little short snorkel tubes that hook onto a mask so that you can swim along on the surface and look down into the water while breathing?
Well, a long time ago I stood on the bottom of a swimming pool with the snorkel extenting out of the water a couple of inches. I was just barely able to breath and the top of my lungs wasn’t more that about 18" below the surfact. The 2’ maximum depth referred to by an earlier poster is marginal but some people might be able to breath with that much pressure.
If you want to do any diving at all, go somewhere and get proper instruction and use proper equipment. Cobbling up some home-made arrangement leads to nothing but trouble.
Though I’m neither planning to do this nor recommending it, I’m not quite able to determine why it should be extraordinarily dangerous. What about this setup conduces toward an embolism?
You forgot to mention how well scrubbed the air in a SCUBA tank is. Think of the oil you inhaled too. Of course a pool is well above an atmosphere in pressure but still.
For those who don’t know, every 33’ we descend into the ocean equals one atmosphere or about 14.7lbs per square inch. Think of our lungs as a balloon. Inflate that balloon and take it down 1 atmosphere and it will be half the size. The same thing happens to our lungs, so we have to breathe in twice as much air to occupy the same space. However the only way to do that is to inhale compressed air. So for every breath we take at 1 atmosphere we are actually breathing twice as much than at the surface. This means if the air was unfiltered we would be breathing in twice the smog or any other contaminant.
Before I became a dive master I was witness to a couple of people collapsing their ear drums in a high school swimming pool during dive training. The instructor at the time had no patients and was virtually dragging people to the bottom of the pool. The students could not master the Valsalva Maneuver (the equalization of air pressure to water pressure).
Most simply an embolism is a ruptured lung or any other part of the body contains expanding gas that has become trapped. As a diver ascends the air he or she inhaled at 1 atmosphere is returning to it original size. Another words a balloon that is fully inflated at 1 atmosphere wants to be twice its size as it ascends to the surface. Either let some air out of the balloon as it ascends or it will burst. Same thing with your lungs, breathe out as you ascend or pop.
Still there is a lot more science and biology to SCUBA but this is just the basics.
Another part of the problem is that you’d be continually rebreathing the air in the hose, if it’s long enough to be a significant portion of your lung capacity or (horrors) exceed same. I don’t need to explain why that’s a bad idea, do I?
Not if you don’t exhale into the hose. Exhale into the water, like scuba divers do.
3m of water is hardly enough depth for any kind of serious pressure effects to develop. I don’t see where this would be particularly bad in a community swimming pool, unless it encouraged you to take these bad habits to deeper water.
OP suggests the hose will be driven by a compressor, with a SCUBA regulator located at depth. The physics would allow this to work fine. Some of the advice regarding the advisability of doing it is probably valid. Since you propose to stay under for “a long time” you may need to consult dive tables, and heed them to avoid ending up bent.
If you try it, use an oil-less compressor for sure. You WILL need a compressor, a fan won’t make enough pressure.
There once was a company that sold such a thing back in the 60-70’s (god I’m becoming an old fart) . The compressor was gasoline driven and floated, IIRC on a innertube. I recall it had two outputs so you and a buddy could dive togethor…as a kid, I wanted one in the worst way.
Absolutely wrong. 3m is plenty deep enough for an embolism or lung expansion injury if the subject doesn’t know what he’s doing. Decompression sickness, while a very, very remote possibility, is still a possibility, especially since the OP mentioned wanting to stay down for a long time.
There’s also the possibility of a shallow-water blackout incident. I don’t know enough about that phenomenon to assess the risk, but I know it’s a possibility.
That’s called a Brownie’s Third Lung. They are pretty neat, except they are almost too easy to dive with so that encourages people to use them with no SCUBA knowledge. I used to use one often, but only at shallow depths because I wasn’t certified. They are expensive, running about 3-grand for a multiple diver setup. It looks like they came out with a smaller one that the OP could use if it didn’t cost $600!