Lets talk about the Physics of pumping air down a hose....

[Bob & Sue]

Experienced divers will recognize problems in the following scenario .
I am not knowledgeable , but have a "feeling" that doesn't sit right .
I just don't know enough about diving to be able to define it ....

You take a pump , and you pump air down into the water thru a hose.
You put a mouth-piece a couple feet back from the far end.
Air flows down thru the hose , passes the mouthpiece , and flows
out the end of the hose.
When you want a breath , you inhale it.
You're walking around in a fresh water lake with 3 ft' of water
over your head .... or shallower .

Does this work ?
Doesn't this work ?
B&S

 

[aquacop911]

What type of setup would that be and what would you use it for? It doesn't sound like it would work for anything cept messin up visibility.

 

[Bob & Sue]

you slip your mouth over the end , and take a breath when you need it...
and just let it bubble out the end , the rest of the time ....
The tube can be a "u" shape , with both ends at the surface , and you have a "tee" at the bottom of the curve .... air flows past the "tee"
and back to the surface ..... you draw a breath when you want one .

What problems do you see ???

Bob R.

 

[BobG]

Are you serious, or don't you know anything about air under pressure and diving?

I'm not a certified diver, but I've investigated the reasons for certification and ignorance of diving technique and hazards will kill you.

 

[bdahunter]

In the 1700's the Spanish came up with a hose and bellows device that pumped air down to an upturned bucket. The air was pushed down into the bucket where it was trapped and divers salvaging wrecks could take a breath and extend their dive.
I don't think it worked very well as they had a lot of fatalities using this system but they did manage to salvage some of the gold and silver. I think they were using enslaved pearl divers to do the work and felt it was a good return on investment.
Probably was, so long as you weren't the slave.

GET CERTIFIED AND INVEST IN SOME REAL DIVE EQUIPMENT BEFORE YOU LOSE YOUR LIFE OR THE LIFE OF A LOVED ONE, PLEASE!

BDA

 

[Bob & Sue]

my impression of these systems is that it isn't "air under pressure" ,
but just a flowage of air down a hose . If something won't work , or simply can't work , I would like to know why ........ I'm trying to gain an understanding , along with some basic knowledge , so if you know something , please pass it on .
I'm retired from work in a government office ... a place where one doesn't get much of a chance to become versed in underwater physical conditions .....
when I introduced myself as a "newbie" .... I wasn't kidding

 

[Royal]

I was certified over 30 year ago and have had well over 700 dive and I tell everyone to get certified if they are gonna use compressed air to detect. They just need to understand what is happening to their body and what to do if in trouble. Lessons are not expensive and are fun.

I have heard people say, I am not gonna go any deeper than six feet. I can not get in trouble at six feet. Yeah, right A person in a panic can embolize in six feet of water.

I have heard people say, "Well I am not going to go deep" Right again If they are on bottom in five feet of water and the goodies work down a slope to thirty, they will soon be at thirty feet. I got a friend down to 100ft on Bonaire without her knowing it. You just can not tell if you are not paying attention.

Plenty of people dive without lessons but they were lucky. Diving is a very safe sport if nothing goes wrong but if it does, knowing what to do sure helps.

I have been in trouble several times but got out of it by using my smarts. Thing is, I got into a few of them by being very stupid. Like diving under the ice alone. That si a bonehead trick

Upshot? I feel everyone should get certified, not a goofy resort class either

 

[Royal]

it is then metered to the breather at the ambient pressure. Makes no difference if you are at ten ft or fifty. It will supply the pressure at the pressure of the water around you.

You need a regulator

 

[Royal]

I agree with you --Get certified!!!

 

[Bob & Sue]

controlling air pressure from a highly pressurized air tank . Isn't Hookah an extremely low-pressure system ?
It would seem that as you go deeper , the water pressure increases quite rapidly .... wouldn't the machine need to deliver more air to you ?
Or , does the machine deliver a constant , set pressure , and the regulator adjusts , so that the diver continues to breathe as easily , as he does at shallow depths ?
I've talked to our local dive shop about PADI classes, and they are reasonably priced , and it doesn't sound too out of line , but it is all scuba , using scuba gear , and free diving .... are the safety lessons relevant to folks using Hookah , and entirely different gear ?
Thanks for all the pointers ..... Much appreciated !!
B&S

 

[Royal]

80psi. It keeps that pressure at the regulator but the regularor only allows the air through at the outside water pressure so you feel no different at five ft or fifty ft.

I can tell when I need to rebuild the compressor because I can not get as deep. One time I was only getting about ten psi out of it.

I wrote a little story about that dang thing sinking and I will try to find it and post it

 

[Bob & Sue]

Or some other time you mentioned it sinking ...It was entertaining to read . One thing I do appreciate about your writing , is that you did
believe me when I said I was a newbie , and prone to ask dumb questions.
Straight forward answers are of great value to us , and all your writings about techniques you use , are very helpful , and help keep our interest at a high level . Once we advance into PADI , and then into Hookah diving , we would hope to be able to be just as helpful to others , who will eventually follow us ....
I didn't know that the Hookah systems built up to that level of air pressure ... 80 PSI seems like lots of PSI's ... Is that much necessary to deliver air down a 60 foot line ?? What differences occurred when
your machine was only pumping 10 PSI .... is it water pressure against your chest that makes breathing more difficult as you go deeper , and the regulator is taking the 80 PSI , and metering it into your lungs just enough to offset the changing water pressure .... is that what's happening ??? B&S

 

[Royal]

I am not pro with this and it has been a heck of a lot of years since I took lessons but you gain 14.7 lbs of pressure every 33 ft you decent. The hookah has to overcome this. The regulator controls the pressure by giving you air at the same pressure of the surrounding water, be it 10 ft or 100. You feel no difference at all. If you were at one hundred ft and the pressure at your regulator was 20 lbs, you could not breath. If it was too high you could embolise. That sucks. Bends cripples you and embolism kills you

All this stuff will be gone over during your lessons, which are fun.

I don't think there is a better way to find treasure for the average detectorist!!

 

[Bob & Sue]

I suspect that the Hookah system has "pop-valves" to release excess pressure .... and that may be a function of the size of the pump , and other (engine) related hardware . The plastic , in-line , cannister holds "extra air" I think .... allowing you a few more mouthfuls , if the pump stops . The regulator , at the mouthpiece , must be the real control for the system ..... adjusting as you work deeper , and as you say , keeping your breathing operating , as if you were still topside .
I know we'll learn all this at PADI , and I'll have lots of questions as we go along , I'm sure .
Based on our experiences in chin-deep water hunting , we tend to agree
about finding so much more out in deeper water .
We also want to spend time photographing, and doing video , of our
evolving hobby interests . For us , the story's almost as good as the treasure !!!
Thanks again , for all the help , Royal . Tonight , I'll read your 4-part posting ... look forward to it !! Bob & Sue

 

[Arkie John]

n/t

 

[Iceguy4]

I kinda looked over this post and never say anyone say "don't hold your breath" I was going to get a hookah and just dive myself, and a family member paid for me to become citified. I can't emphasize strongly enough...get citified. Are you aware that you are at a greater risk of an embolism from a depth change from 10' to the surface then you are from 100' to 90'.if you hold your breath?

 

[Arkie John]

n/t