# How long can a snorkel tube be and still be effective? **URL:** \ **Category:** Factual Questions\ **Created:** [April 28, 2006, 9:05am UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567 "2006-04-28T09:05:20Z")\ **Posts on this page:** 15\ **Page:** 3
**Author:** ![Tripler](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripler/32/21807_2.png) [@Tripler](https://boards.straightdope.com/u/Tripler)\ **Post date:** [April 30, 2006, 4:42pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/41 "2006-04-30T16:42:55Z")
Another thing to throw out into the mix: doesn’t carbon dioxide _sink_? I seem to remember something about this, and this would in effect limit the length of the tube (all other factors notwithstanding). Sure, you could exhale as hard as you can, but eventually the carbon dioxide buildup would “plug” the bottom of the snorkel thus blocking any valuable air. IIRC, this is why they have to pump fresh air into mines, and why well digging was so dangerous back in the ol’ days. . . Tripler I could be wrong. I’ve been wrong before, I’m sure I’ll be wrong again. ---
**Author:** ![flex727](https://avatars.discourse-cdn.com/v4/letter/f/258eb7/32.png) [@flex727](https://boards.straightdope.com/u/flex727)\ **Post date:** [April 30, 2006, 4:44pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/42 "2006-04-30T16:44:55Z")
> [@Rick](#): > > I think that **flex** and **slaphead** are describing similar but very different conditions. > In flex’s experiment he is at the bottom of the pool, all parts of his body are exposed to the exact same pressure. he puts his mouth on a garden hose and tries to inhale. He did not mention what happened (other than no physical damage), but I am guessing that he did not get a lung full of air. This would be caused by: A) the pressure at the bottom of the pool, and B) the pressure of the pool probably squashed the hose flat. ☹ Just to add a couple of data points to this discussion: 1. When I tried to inhale, it was like trying to inhale on a solid pipe. I could pull no air in. I felt no force trying to push air out of my lungs (but considering the passage of time, I will admit my recollection could be faulty). 2. The hose was not flattened at all. ---
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [April 30, 2006, 5:21pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/43 "2006-04-30T17:21:20Z")
> [@flex727](#): > > I felt no force trying to push air out of my lungs… No, you wouldn’t. One of the drills in SCUBA is to remove the regulator from your mouth and to put it back in. (Just in case it gets knocked out or something.) You just hold your breath. No worries. On my first open water dive the instructor pried a shellfish off of a rock and ate it at 65 feet (about 3 atmospheres). ---
**Author:** ![flex727](https://avatars.discourse-cdn.com/v4/letter/f/258eb7/32.png) [@flex727](https://boards.straightdope.com/u/flex727)\ **Post date:** [April 30, 2006, 5:54pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/44 "2006-04-30T17:54:01Z")
> [@flex727](#): > > Well, you and **Mangetout** are fairly persuasive and cause me to re-think my position. However, until I complete that process… Upon further reflection, I agree that there is _some_ force exerted trying to push water up the tube. It seems to me that the total force would be the total weight of the water that would fill the tube minus the weight of the air in the tube. There may also be factor of 0.5 involved (i.e. divide by 2), but I’m still haven’t worked it all out yet. That force, if it’s a relatively narrow tube, would likely not be enough to cause any damage at swimming pool depths. At 100’, it might be a different story. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 30, 2006, 8:50pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/45 "2006-04-30T20:50:34Z")
> [@flex727](#): > > Upon further reflection, I agree that there is _some_ force exerted trying to push water up the tube. It seems to me that the total force would be the total weight of the water that would fill the tube minus the weight of the air in the tube. There may also be factor of 0.5 involved (i.e. divide by 2), but I’m still haven’t worked it all out yet. That force, if it’s a relatively narrow tube, would likely not be enough to cause any damage at swimming pool depths. At 100’, it might be a different story. That doesn’t sound quite right; the pressure is coming from the fact that you’re under a massive pile of water that wants to fill the tube back the the surface level; that the tube is big or small doesn’t affect the magnitude of the pressure, as far as I can work out. It will affect the _amount of work_ that the system can perform; so a narrow tube will suck really hard, but only briefly until it’s filled (either with water, or parts of the hapless diver). A wider tube will suck just as hard (no harder), but for loger, or more voluminously. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [April 30, 2006, 8:56pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/46 "2006-04-30T20:56:37Z")
> [@Tripler](#): > > Another thing to throw out into the mix: doesn’t carbon dioxide _sink_? I seem to remember something about this, and this would in effect limit the length of the tube (all other factors notwithstanding). > > Sure, you could exhale as hard as you can, but eventually the carbon dioxide buildup would “plug” the bottom of the snorkel thus blocking any valuable air. > > IIRC, this is why they have to pump fresh air into mines, and why well digging was so dangerous back in the ol’ days. . . > > Tripler > I could be wrong. I’ve been wrong before, I’m sure I’ll be wrong again. Carbon dioxide is heavier than air, but not so significatnyl that’s it’s likely to be a significant factor in a system that is turbulently circulating (otherwise it would also pool in the unexpelled air volume in our lungs). Far more significant (apart from the pressure considerations, etc), is that, on reaching a length of tube containing a volume of air equal to the lung capacity of the experimenter, there’s simply no way for thim to expel the exhaled breath all the way out of the tube in order to get fresh air to breathe in again. ---
**Author:** ![spinky](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@spinky](https://boards.straightdope.com/u/spinky)\ **Post date:** [May 1, 2006, 12:37am UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/47 "2006-05-01T00:37:34Z")
> [@SentientMeat](#): > > I’m sure you’re right - thinking about it, it would be like being hugged by a very strong grandmother. Is there a world record for this or something? For strong grandmothers? I think I might have seen something about that on ESPN3. ---
**Author:** ![seenidog](https://avatars.discourse-cdn.com/v4/letter/s/f04885/32.png) [@seenidog](https://boards.straightdope.com/u/seenidog)\ **Post date:** [May 1, 2006, 12:52am UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/48 "2006-05-01T00:52:52Z")
easy way to test. You can suck in and blow out with about the same force. Take a tube of the diameter of your proposed snorkle, and see how far underwater you can put it and still exhale. Like a bucket of water, you will not need a very big bucket. I am guessing it will be about 18" maybe a lot less. That is the same depth you could suck air in. Funny thing about gravity (Which creates air pressure), it works every time. ---
**Author:** ![hattePogesehen](https://avatars.discourse-cdn.com/v4/letter/h/838e76/32.png) [@hattePogesehen](https://boards.straightdope.com/u/hattePogesehen)\ **Post date:** [January 27, 2016, 6:07pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/49 "2016-01-27T18:07:10Z")
could you encase your chest in a sealed container with air inside that would be light enough to allow submersion, so not too much air space that would just bring you to the surface, and a series of weights you could carry and drop should something go wrong. Thus you could still breath underwater, no pressure issue. I guess you would in theory need to make yourself a submarine? This could work, don’t give up on your dream, unless you have already drown. On second thought, maybe its the diaphragm you would want neutralize the pressure for? I’m linking a picture. The chest depressurization suit would space to allow chest movement, would the air need to be removed? On second thought, the chest piece could have an mechanically assisted expansion feature that allows expansion when the chest expands. I guess air has a buoyancy of about 8lbs per gallon. Here’s a rough idea of what something like that might look like [http://s17.postimg.org/wbad1yd33/Breathe\_under\_water.jpg](http://s17.postimg.org/wbad1yd33/Breathe_under_water.jpg) ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [January 27, 2016, 6:13pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/50 "2016-01-27T18:13:59Z")
> [@Tripler](#): > > Another thing to throw out into the mix: doesn’t carbon dioxide _sink_? I seem to remember something about this, and this would in effect limit the length of the tube (all other factors notwithstanding). That doesn’t help. But setting aside air pressure, probably the biggest limitation is that your lungs cannot exhale enough volume to evacuate enough CO2 from a long tube. It would basically be like breathing into a bag. ---
**Author:** ![Whiskey\_Dickens](https://avatars.discourse-cdn.com/v4/letter/w/9fc348/32.png) [@Whiskey\_Dickens](https://boards.straightdope.com/u/Whiskey_Dickens)\ **Post date:** [January 27, 2016, 7:01pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/51 "2016-01-27T19:01:01Z")
> [@hattePogesehen](#): > > I guess air has a buoyancy of about 8lbs per gallon. > > Here’s a rough idea of what something like that might look like > > [http://s17.postimg.org/wbad1yd33/Breathe\_under\_water.jpg](http://s17.postimg.org/wbad1yd33/Breathe_under_water.jpg) Great drawing! Also, you basically just invented an old timey pressurized diving suit! But, like the bikini version. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [January 27, 2016, 7:53pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/52 "2016-01-27T19:53:09Z")
> [@Mangetout](#): > > That doesn’t sound quite right; the pressure is coming from the fact that you’re under a massive pile of water that wants to fill the tube back the the surface level… This. I once laid on my back on the bottom of a hot tub, with a copper-pipe snorkel to the surface. I could breathe, but only with very great effort. If you were to look straight down at me from above, you might estimate my chest to have an area of about 1 square foot. At a depth of two feet, that means I had two cubic feet of water pressing down on my chest. Water has a weight of about 62 pounds per cubic foot, so I had about 124 pounds of weight pushing down on my chest, trying to squeeze the air out of it through that snorkel. Someone trying to breathe through a snorkel with their lungs at a depth of three feet would feel like they had 186 pounds parked on their chest; it would likely be impossible to inhale at this point. This is why SCUBA gear uses tanks of high-pressure air with a regulator to automatically supply air to the mouthpiece at a pressure just a smidge below local at-depth pressure (“a smidge below local” so that it doesn’t release any air until you lower the pressure inside the mouthpiece a smidge by trying to inhale). IME these regulators are exquisitely sensitive: I can feel the difference in breathing effort that is required when in a vertical orientation (lungs 1’ below regulator) versus a prone orientation (lungs at exact same depth as regulator). It occurs to me now that whales, esp. the very largest ones, must have immensely strong breathing muscles; with their blowhole just above the surface of the ocean, their lungs are surely several feet below the waterline. inhalation must require a lot of effort. ---
**Author:** ![Crazy\_Canuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crazy_canuck/32/5282_2.png) [@Crazy\_Canuck](https://boards.straightdope.com/u/Crazy_Canuck)\ **Post date:** [January 27, 2016, 9:01pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/53 "2016-01-27T21:01:42Z")
[inevitable zombie joke] Everyone knows that zombies don’t need snorkel tubes, as one of the perks of being undead is ignoring the whole breathing problem. [/izj] I almost missed this being a zombie thread, as no one from the first 48 posts made almost 10 years ago was banned. I think that says something about divers, but I’m not sure what yet. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 27, 2016, 9:41pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/54 "2016-01-27T21:41:47Z")
I noticed it was a zombie when I saw **gabriella** ’s name. She was a great contributor to the board, back in the day. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [January 27, 2016, 10:21pm UTC](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567/55 "2016-01-27T22:21:27Z")
Also, if you have ever used one of these pressurized-hose breathing apparatuses, then you know there is a real risk of somebody farting in the intake tube. I mean if you were in the Army Engineer Corps, I have no idea how frequent this is in the private sector. [Previous page](https://boards.straightdope.com/t/how-long-can-a-snorkel-tube-be-and-still-be-effective/354567.md?page=2)