Diving under water regarding air?

Question

I was swimming in my pool today, then this idea came across my mind that i could breathe if i had my snorkel and trapped air in a plstic bag connected to each other by a rubber band. Then it hit me that this might be a very stupid idea because it may be possible to pass out or die by way of carbon dioxide poisoning from excessive inhalation of the replaced air in the bag or passing out or dying from pressure difference when under water. Was only thinking about this for a dive at max 15 feet. Let me know what you think and If possible tell me the science behind it because I havnt't studied this yet. I am willing to try it, but I don't want to pass out or die because I like to dive, but can't hold my breath for a long time.

Answer 1

There is already air trapped in a bag at your disposal.  It's called your lungs.  The plastic bag just increases the total volume.  You'll still eventually use up all the oxygen and be forced to surface.

The assertion that you will pass out is ridiculous.  You'll cry for air long before you actually faint, unless you hyperventilate or do something else similarly misguided before you dive.  You could save yourself some trouble by just closing your lips and nose and breathing the same air in your mouth.

Answer 2

You should read the body's instruction manual, we don't like to breathe carbon dioxide!

Unfortunately it's what we exhale

Answer 3

bad idea lol, you'd be rebreathing the air you exhaled, and you would eventually pass out.....and die if you're down that far.

Answer 4

get an O2 tank

Answer 5

In a sense, what you are describing is a rebreather - a form of SCUBA (self contained underwater breathing apparatus) which gives off almost no bubbles because when the breath is pushed out, the CO2 is absorbed by chemicals and O2 is added to the mix.   Awkward and a bit expensive, so most divers use compressed air and just blow off the exhalations as a mass of bubbles.

  The real problem with your idea is the awkwardness of handling the bag under water, where its bouyancy is constantly arguing with your desire to go down.  I do agree that taking a diving course will increase your knowledge and confidence in your safety.

Answer 6

The first problem you would have is that at 15 feet, the bag would collapse to almost half of its volume.  The second problem is that you are just increasing the dead space that includes your trachea and bronchi as well as the snorkel and bag.  The third problem is that you will quickly need to hyperventilate because the carbon dioxide in your blood will continue to rise as you fill the dead space with it.  The fourth problem is that you will not be getting much additional oxygen.

I strongly suggest that you take a scuba class and get certified to dive.  It will teach you how do dive safely using modern equipment.  Diving is also a great deal of fun if you know how to do it.