SCUBA gear and boat cleaning...

[Herb Parsons]

Hot Dawg!

Fred and I not only agree totally on something (and admit it publicly) we both pulled the same test.I had heard in class, that most people physically cannot inhale surface air deeper than 5 feet. I simply took it at face value. 2-3 years later, a friend told me about how he and a buddy "snorkled" 15 feet deep in a quarry near their house. I didn't believe him, but didn't want to say he was full of it (I was a little more timid back then) without knowing for sure.I hooked two snorkles together, for a total of about 2 1/2 feet. I got about two feet down, and found that it was taking me about 3 seconds to inhale each breath, and an immeasurably short time to exhale (basically, the water just forced it out of me). I couldn't have kept doing it for long without exhausting myself.The experiment proved two things to me. The instructor was right, and the forces of water pressure are far stronger than we realize.

 

[Jack Hart]

Question for Brian?

Did you have any clue that you question(s) would get this much response? I think it is great that we can all learn so much by using this forum.Jack Hart

 

[Herb Parsons]

PADI Swim Requirements

While I couldn't find anything specific on PADI's site, I did find several web sites that are PADI authorized, and they seem to have a common requirement for open water certification:200 meters swimming10 minutes treading water

 

[r.w.landau]

Franklin, the difference....

If you fill your laundry tub full of water. Then take a glass and turn it upside down. Push the glass to the bottom of the laundry tub. If the water is clear enough you should see that the air has compressed and that the water level inside the glass has compressed the air and risen up from the rim. As you raise the glass, the compressed air pushes the water out so that it is even with the bottom of the glass. When you get back to the surface of the laundry tub, there is no extra air!Next, put the glass on the bottom of the laundry tub then fill it with air (via a hose). Then as you raise the glass the air expands and bubbles will come out from the glass.With that in mind, if you breath compressed air 4' down, hold your breath, and rise to the surface, that air expands in your lungs.The pressure in your lungs is one atmosphere per 33'. An atmosphere is equalivilant to the pressure that the earths' atmosphere put on you at sea level.Hope that helped!I agree with Fred, love your stories, stick around.Herb, don't push it with Fred, he'll go into research mode!r.w.landau

 

[Richard19068]

water hose

The problem with breathing through a 10 foot hose, assuming you could do it, is that the old air in the hose wouldn't get exchanged enough to replenish it with fresh air. It would be the same hose full of old air going in and out of your lungs and soon be depleted of oxygen.

 

[Franklin]

hose

I deleted it after reading a post I missed saying that it's too hard. However, I was thinking of exhailing through the nose, not the hose.

 

[Franklin]

gonna have to try it

this weekend.Most of the hull is within 2' feet of the surface. I assume it's the depth of the lungs and not the head but I think it's close enough to try anyway. Currently I take a deep breath and dive down and was going to do that this weekend anyway to check the zincs. Now I got something else to check too I'll let you know how it goes and I'll exhale before coming up.

 

[Capt Ron;-)]

Bubba Scuba

Brian, I was diving in the early sixties, only cert was with YMCA, I finally did a course. Lotta stuff can go wrong the deeper you dive. The phyisics and physiology are against us, we are designed to hold our breath below the water, and that's fine, people have gone over 300' on a 'free' dive (lungs beginning & ending with 14.7 psi). I'll stop there: I owned a shop, and had an instructors certificate in, YMCA, NAUI, and PADI. Taught many certificayion classes. To answer your question specically 1) there is no law that says you cannot dive withuot certification. 2)Some shops wil fill (many in fact) if they beleive you about just diving on your boat. No You will not embolise in 8ft of water, although it is 'technically' possible, expecially with mucus in the alvioli.Trouble, you may drop a zinc or be tempted for deeper...get certified. Padi courses are not the best but they're like a cheap car; everywhere. Barring that get the Jeppeson manual from a library. 90% of all cases of embolisims are indeed fatalitys

 

[Ross]

In the breathing through a

hose plan see how high you can suck water up a clear hose and how deep you can submerge it and still blow bubbles.

 

[kendall]

once did just that

when I was younger, maybe 12 or so, swimming in the canals, roughly 5ft down you could breath through a 10ft x 1/2in pvc pipe, not too difficult, much more than that and it got too hard to breath so you couldn't do anything stressfull.  hookahs or however it's spelled, I'm still thinking over, don't see any issues if you were to stay in your depth.ken.

 

[Herb Parsons]

Kendall

Either your memory is flawed, or you were one tough 12 year old kid.Do the math. At 5 feet depth, there is 2.45 lbs per square inch. Let's say your 12 year old chest area was 10 inches x 10 inches. That would be 245 lbs of "weight" pressing down on your chest.But wait, there's more. Water pressure is omni-directional, meaning that you also had the same pressure pushing from the other side. So, now we're up to 490 lbs of pressure.But wait. Act now, and there's even more. Let's call it another 3 inches on the sides (and there are two), so that's another 147 lbs.So, at 12 years old, you had roughly 600 lbs of pressure pushing in on your lungs, and you found it "not too difficult" to breathe? Wow, I'm impressed. And that says a lot, coming from me. I mean, I'm the kid that walked 10 miles to school, in the snow, barefoot, uphill, both ways.At least, that's the way I remember it.Guys, this is physics. Just the way it is. No doubt, some folks can SCUBA with no instructions, and do it without ever taking a lesson or learning a thing about how it all works, and do it without injury. No doubt some folks are just that lucky.I'm not much into trusting things to luck though.