fishermantwo
Well-Known Member
Actually I said 50% of the local yachties own one. I did a pole. So out of the 20 boats 10 have them. Another has tanks but used to have a hookah and regrets selling it.
Hookah Diving
- Thread starter steveallan
- Start date
Actually I said 50% of the local yachties own one. I did a pole. So out of the 20 boats 10 have them. Another has tanks but used to have a hookah and regrets selling it.
Skylark
Well-Known Member
I'm assuming that some sort of basic training is required?? A simple understanding of Boyles Law (pressure-volume relationship) shows that there is the greatest change in volume in the shallows. A full set of lungs at 2m, breath held, would have expanded by 20% by the time you've reached the surface, may be enough to burst the lung. Also, some people have problem in equalising ears in the shallows. A burst ear drum could occur from surface to under the keel.
If you're going to get some training, why not do a basic scuba diving course?
I've never experienced hooka gear so it's wrong to give an opinion. Scuba, on the other hand, is not so difficult. There's a clue to its advantage in its name "self contained".
If you're going to get some training, why not do a basic scuba diving course?
I've never experienced hooka gear so it's wrong to give an opinion. Scuba, on the other hand, is not so difficult. There's a clue to its advantage in its name "self contained".
steveallan
Well-Known Member
ghostlymoron
Well-Known Member
You may be correct in your conclusion but I don't think your physics is correct. At 2m depth, the absolute pressure will be 1.2 bar, however, the air pressure inside your supply pipe will still be 1bar. So the differential is only .2 bar which is what you will have to overcome.
prv
Well-Known Member
Yep - the error comes from mixing gauge pressure and absolute pressure.
Still, that's about 3 pounds per square inch. How many square inches is the surface of your chest, and are your intercostal muscles strong enough to lift that many pounds? I suspect not.
Pete
savageseadog
Well-Known Member
It's best to dive without smoking drugs
It's impossible to breathe atmospheric pressure air at a depth of 0.5m plus. Regarding embolism risk any air breathed in from any pressurised system at depth will be approximately at the ambient pressure regardless of the fact the air is free flowing or not. There is a quantifiable risk especially as breath holding is instinctive.
It's impossible to breathe atmospheric pressure air at a depth of 0.5m plus. Regarding embolism risk any air breathed in from any pressurised system at depth will be approximately at the ambient pressure regardless of the fact the air is free flowing or not. There is a quantifiable risk especially as breath holding is instinctive.
electrosys
Well-Known Member
If you're thinking of making your own system, the use of a two-hose mouthpiece (as used on the old honky-tonks - I loved those !) would allow excess air to escape behind you - one reason why some photographers prefer them. Ebay: #260941303223
Providing you stay above 30 feet there'll not be any problems with decompression etc. (assuming you're not diving in a lake at high altitude, or flying the next day), so if all goes pear-shaped, you can simply abandon the gear and go straight up to the surface - whistling as you go, of course.
Another approach would be to buy an out-of-date full-face-mask-respirator as used for firefighting aboard ships, and modify the 2nd stage regulator (built into the mask) for even lower pressure use. I bought a couple at a boot sale many years ago with this in mind, but never did get around to it. The regulator is made of brass etc, so would be suitable for use underwater.
Providing you stay above 30 feet there'll not be any problems with decompression etc. (assuming you're not diving in a lake at high altitude, or flying the next day), so if all goes pear-shaped, you can simply abandon the gear and go straight up to the surface - whistling as you go, of course.
Another approach would be to buy an out-of-date full-face-mask-respirator as used for firefighting aboard ships, and modify the 2nd stage regulator (built into the mask) for even lower pressure use. I bought a couple at a boot sale many years ago with this in mind, but never did get around to it. The regulator is made of brass etc, so would be suitable for use underwater.
electrosys
Well-Known Member
I'm not sure exactly where measurements ought to be taken from, but someone snorkelling with their body vertical, with their head completely submerged - the bottom of their chest cavity would be some 2ft below the surface.
Now although 'body vertical' is an unusual position for snorkelling per se, it's a position scuba divers often present, with their weight belts and tanks etc - and breathing through a snorkel like that is no problem whatsover.
So - if 2 feet is manageable, would 6 feet (which should be enough to clear anyone's prop) ? Worth a swimming-bath experiment with a 'long' snorkel, I'd have thought.
Short while later ...
To answer my own question - Yes, 6 ft would be possible. I've just conducted a quick experiment, by standing on the deck of a boat on the hard, and sucking up water in a tube from ground level. 8 ft was no problem (at which point I ran out of tube), indicating that the lungs can tolerate a negative pressure of 8ft of water without difficulty.
Of course, with a 'long snorkel' you'd need to add a couple of flap valves to ensure you don't inhale your own exhaled breath, either that or discipline yourself to exhale through your nose or the side of your mouth.
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ghostlymoron
Well-Known Member
So my idea is possible (for someone with reasonable lungs) and it could also be used on a boat with no electrical power and single handed.
flipper
Well-Known Member
So my idea is possible (for someone with reasonable lungs) and it could also be used on a boat with no electrical power and single handed.
I guarantee you will not be able to breath through a six foot snorkel. With a normal snorkel, try getting someone to push your head under the water until only the tip is out of the water - you can feel the lung squeeze.
fishermantwo
Well-Known Member
So my idea is possible (for someone with reasonable lungs) and it could also be used on a boat with no electrical power and single handed.
Search youtube for examples.
prv
Well-Known Member
I agree if we're talking about someone taking a breath at depth and then holding it as they surface. But I understood Pmyatt's comment as referring to the fact that the hose is connected directly to the open end of a snorkel. I thought he was worried about air above ambient pressure thus being forced into the lungs, regardless of any movement up or down in the water.
Because of the valve in the snorkel, this wouldn't happen.
Pete
prv
Well-Known Member
So why do you think nobody does it? Is there some global hookah-maker's cabal that forces even penniless subsistence fishermen to buy their pumps instead of using a simple length of hose?
Pete
LadyInBed
Well-Known Member
ghostlymoron
Well-Known Member
Mistroma
Well-Known Member
Ah, I knew it wouldn't work due to the pressure differences involved. So I guess his admission that he could only manage 3 feet does tend to support earlier arguments (see his reply to questions about depth below the video).
PS
I haven't dived for many years but did once try an old Cousteau style twin hose system where the regulator sat between my shoulder blades. As I swam around I either had to suck like mad or had air forced into my lungs depending on attitude in the water (wonder how long before some one comments on alt. meaning of attitude). No wonder the modern design caught on very quickly.
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prv
Well-Known Member
Um, yeah. Notice where his head is all that time? The top of it's sticking out of the water. So his ridiculous bucket and hose arrangement achieves precisely nothing over an ordinary snorkel.
Pete
BobPrell
Well-Known Member
I read one of Cousteau's books at least 50 years ago and he said that was one of the first things he tried, just sucking the air down. He found it a completely ineffective.
Lady in Bed, It was recollections of old movie with helmeted divers that made me think of a manual pumping system. Thanks for picture.
William_H
Well-Known Member
Stop it stop it I am sure the swollen head will cause problems diving. (but thanks anyway)
I am not very fit and 20kg heavier than I was 40 years ago however I usually clean the boat with no weights and no wet suit. My boat is relatively small so that I can hang monkey style on one arm on the gunwhale and rest or clean the upper most part of hull with snorkel top out of water. I then do a kind of duck dive the momentum takes me deep enough to be able to grab the bottom of the keel. That makes it easy to scrub the keel sides until something tells me it is time to go up. Then there is a period of puffing to recover breath. One kindly passer by asked if I was oK once. He thought I was having a heart attack. I do find that if I expell all the all from my lungs before taking a lung full before descending that I last longer or recover quicker.
The under body of the boat is easier as buoyancy holds me against the hull.
I generally don't wear fins. I only occasionally wear a wet suit in the cooler months. This would be essential in UK of course. Hence you need to wear some lead weights. The amount will take some experiment to get right. I wear 2 weights on a belt with just a wet suit top (or light weight steamer wind surfer wet suit) or 4 weights with top and bottoms. 6mm diving type suit. To be honest it is such a struggle to get the suit on and off that I avoid if possible. You need enough lead that when swimming you have as much buoyancy as without wet suit. Or it has been described that you should be able to float vertically with water line just across the face mask. Too much lead means it is too hard to float and recover too little means it is too hard to get to the keel. Weights are usually worn around waste however I have found it nicer to have some weight on ankles to keep legs from floating too much.
SWMBO wants to swim each morning near home and at the mooring site. I am obliged to go with her. I detest swimming up and down so just swim to the boat and caress her bottom. (the boats) Hence the a/f paint doesn't last long but it is always clean. The weed can grow noticeably in spots where a/f has rubbed off over 2 or 3 days when weather is hot and sunny.
So for your boat if you can swim on it several times cleaning parts only each time it can be fun rather than a big effort. I reckon 15 minutes cleaning is my limit. Give it a go but do wear fins at least at first due to tides and if you can't do without wet suit then get one. good luck olewill
fishermantwo
Well-Known Member
Actually i meant the video of the bloke in the water using a hookah and his mate pumping a hand pump. I can't see it at the moment. Long hose by its self wont work. With the old style snorkel before valves, the length before it becomes unsafe is fairly small, something like 18 inches. New generation snorkels with valves and the tube computer designed for efficiency are a revelation to use. I can clean my folding prop using a snorkel. Holding your breath and working under the boat when your getting on in years is asking for trouble. This is where the hookah comes in to its own.