"Extra Air" in submerged bucket?

[Pinggene]

My son & I were talking the other day & came up with an idea (no we did not try it yet), and we were wondering if anyone else has ever tried it...may be dangerous...if so, please state it like it is & tell us why you think it may be.

What would happen if prior to spearfishing, one would put a 5 gal bucket filled with air (it would be upside down) on the bottom. (Would need to weight it down or tie it to something.

Then, when you wanted to have a bit more bottom time, one would expell some of their "lung" air to clear the snorkle, & then put one's snorkle into the bucket to get a breath or two of fresh air & stay on the bottom a bit longer.

I know it sounds crazy, & I would not try it at 30M, but at 10M or less, I don't know why it wouldn't work. Thoughts?

Gene

[Jon]

Air embolism (=death) comes to mind.

I wouldn't try it.

Jon

[Pinggene]

Jon,

Can you define "Air Embolism" & why you think it would happen? Just trying to understand.

Thanks.

Gene

[bjpete]

Listen to what Jon said, If you haven't taken a basic SCUBA course, then you probably haven't heard of the different gas laws, simply stated it's this: increased pressure (increase in depth), a given volume of air will be reduced, decreased pressure (rising to the surface) a given volume of air will expand. If you have your lungs full of air at depth and ascend then air in your lungs will expand which could be bad news. In SCUBA diving we train our students never to hold their beath while using compressed air, you must always be breathing (both in and out).

[trux]

The risk is simply not worth of it, and especially not if you dive with children.

1. Not only you can suffer a barotrauma as Jon wrote when surfacing (or changing the depth during the dive) without exhaling adequate volume of air, but ...
   .
2. ... you also risk to choke when trying to take your breath, which unlike at the surface can be fatal at depth.
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3. Another reason to avoid it is that by artificially prolonging the dive, and by inhaling air of higher than atmospheric pressure, you increase the risk of DCS (bents / decompression accident due to Nitrogen bubbles released by the tissue when depressurizing during surfacing).
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4. The next serious risk factor is that by just re-filling your lungs without proper breath-up, you change the CO₂/O₂ ratio in your lungs and make so very difficult to the brain to recognize when you really need to breath. It means higher risk of hypoxic blackout.
   .
5. Having higher volume of pressured air in lungs, with high level of CO₂ seriously increases the risk of CO₂ blackout - CO₂ is toxic at higher levels, and since you manage to get more air (hence also more CO₂) into your lungs without ventilating, and also staying longer submerged, you expose you much more to the toxic effect of CO₂ than normally.
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6. By keeping the bucket open for a longer period can be dangerous - especially in lakes or caverns, or in seismically active locations, there may be methane or other gases escaping from the bottom, and can get into your bucket. Inhaling such toxic gas from pockets in caverns or from Kesson bells without purging it previously with clean air, is one of very common reasons of fatal accidents.
   ..
7. By the maneuver and the stress it adds, you may actually lose more than you gain, and will probably not manage to prolong the dive seriously anyway.

If the pure freediving is not satisfactory enough to you, I suggest that instead of taking this risk, you sign together with your son to a Scuba course; learn more about the theory; and drill the proper and safe way of diving.
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[Marwan]

to add to all the points above, if you try it at 10 meters and for some reason it doesnt work, you still have to go up 10meters with no air in your lungs, my first thought would be a bad blackout...

[maytag]

Just yesterday I was doing a search here on caves and came across this really interesting thread on bells - I think it's relevant to your question of inverting a bucket:

http://forums.deeperblue.net/general...highlight=cave

Cheers & safe adventures,

[Pinggene]

Thank you for the info guys. I will not try it. I enjoy life too much to risk it for a little extra bottom time.

Happy Holidays.

Gene

[richiedubya]

Tis is actuallyy not a new idea. The booK neautral boyancy describes how Greek sponge divers practices this technique to extend their bottom time duritng dives. However I would not reccoend you trying this for yourself.

[deep thinker]

Like trux said a blackout is a very possible result because you havent ventilated properly. I wouldnt want to out anybody through that stress in the water it is quite a scare and something I think most of us want to avoid, seein that it can happen at any depth I wouldnt try it but I can understand the temtation of wanting to try something like this, its just a natural train of thought to want to increase the time you can be under water.