Homemade snorkel-bellows diving apparatus for hull cleaning

[Diesel Bill]

I remember training for certification back in the mid 1970's. The dive shop had a 5 foot long snorkel and we were encouraged to try it in the deep pool. I started breathing at the surface and all was well. As I started going down slowly at the 1 foot level I could feel the pressure of the water on my chest as I inhaled. At the 2 foot level it was very hard to inhale, and at the 3 foot level it was impossible to get any air.

[Offshore454]

When I mentioned contaminated air from a compressor that wasn't built to supply air for breathing, I wasn't talking so much about oil or dirt. I'm much more concerned with carbon monoxide. If the air intake in anywhere close to a running internal combustion engine, like a boat engine or generator, it will get sucked in as well. Divers have died because professional scuba tank filling stations have had the air intake somewhere in proximity of a road where someone parked a running car or truck, and the wind just happened to be blowing the right direction to allow the exhaust to enter the compressor intake.

The only two "Non scuba equipment" options I've seen in this thread are to, from five feet under water, try and suck air through a hose with the other end at the surface, which is impossible, or use a compressor that was not built to produce safe air for breathing. So, impossible idea, or possibly dangerous idea.

Like I said, the compressor idea would work, but has risk. You wouldn't even need a valve. Scuba second stages are built to stick open when they fail rather than sticking closed because it's still possible to breath from a free flowing regulator.

My recommendation is to go get your basic open water certification. It's easy to do, and doesn't cost that much. Then you could buy decent used gear and have it serviced by a reputable dive shop.

[foufou]

I put together such a hookah system with an oil less compressor and the second stage of a scuba regulator. The tricky part was finding threads compatible with the regulator input. If I recall correctly it turned out to be compression threads from an under sink supply line. And I found out cleaning bottoms wasn't so much fun

[chris mac]

Originally Posted by sailm8

How do the mermaids at Wichee Wachee springs use the air hoses they breath through? It's just a hose that is bubbling air. When they need air they exhale and take a hit from the hose. They are in 10 or 12 feet of water.

That is taught in scuba course, at least it was when I learnt in the early nineties. If your hose ruptures, you can breath the bubbles as you ascend.
Just do not suck on the hose(pressure), and do not hold your breath.
Think of it like drinking from a garden hose.
The other thing I wanted to address is using cheap oil less compressors. If they have a steel tank, compressed air(especially humid air) releases water into the tank. Rust builds up quick and contaminates your air.
I don't personally like the idea of a lungful of rust.

[a64pilot]

Back in the 70's when I got around to being certified by the Y, we were even taught to breathe directly from the tank. Trick was to crack open the valve of course BEFORE placing your mouth on it

[Cormorant]

If you scroll down to post #3 in this thread:
http://www.cruisersforum.com/forums/...ne-180145.html
Cotemar gave a very good recipe for a DIY hookah.

[BobLocal60]

I was certified NAUI in 1989 or 90 at MDA in Gaum... I bought a hookah system in 2014 and used it 3 or 4 times, in 2016 I bought some used dive gear and find it much more comfortable to use to clean the boat... $750 invested in a barely used 2 cylinder battery operated hookah system with 2 second stages & total of 60' of hose available for $450.00

I also was a navy NAWSPI and did my last couple years as a safety diver / instructor as NASP.

[captlloyd]

Originally Posted by a64pilot

Back in the 70's when I got around to being certified by the Y, we were even taught to breathe directly from the tank. Trick was to crack open the valve of course BEFORE placing your mouth on it

You beat me to it a64pilot. Yes, you can breath directly from a scuba tank in an emergency situation which proves that all you need is enough pressure and volume. If you were to use a scuba tank for a hooka system you would still need to be certified to get the tank filled. You can put your own hooka unit together, there is a lot of info on this . Oil, rust, a filter system will take care of that, but as stated, be very aware of carbon-monoxide contamination.

[Nani Kai]

I am a NAUI Master SCUBA instructor with over 42 years experience, 5000+ SCUBA dives in every imaginable condition and thousands of additional hours on snorkel. I have scrubbed many a boat hull. Your design as described won't work. When water gets into the 5' tube leading to the surface (and it will) you will not be able to purge the water back out the tube with lung power even if the air being pumped from the surface is equal to the ambient water pressure on your chest. Take a five foot length of pvc out in the yard, fill your mouth with water and try to blow it out the top. The air pressure coming from a foot operated dinghy pump (assuming it actually reaches your mouth in anything resembling useful volume) will be highly variable which means sometimes you won't have enough pressure to fully inflate your lungs and other times you'll have too much. On the intake cycle of the pump you won't have any air as your diaphragm isn't strong enough to overcome the ambient water pressure and draw air from five feet away. Carbon dioxide will definitely build up in the angles and curves of your system. CO2 excess, while not as immediately toxic as CO is still not a condition to trifle with underwater. The CO2 build-up will make you breathe faster which will create more CO2 which will make you breathe faster, which will........etc, etc. Assuming your heart is in good shape and you're not at high risk for a stroke your escape plan to come to the surface when you feel uncomfortable is pretty much the same as diving down, holding your breath until CO2 builds up in your lungs and then coming up. Dragging 12-14' of semi-rigid pipe around (five down, five up and a foot or two each side of your face for the curve) will be ridiculously difficult. 12' of 3/4" pipe will displace something in the neighborhood of 113 cubic inches of water which will require 4.18 lbs of weight to keep from floating up. Hook a 4 pound weight on your snorkel and see if you can keep it in your mouth. A Hookah rig will work but they are expensive and also carry their own set of safety concerns. SCUBA is where you want to be. Used gear can be purchased from most Dive Shops, especially in a area where a lot of charter diving is being done. Shops in high volume markets usually replace their rental gear every year. You will probably get an even better deal if you take your SCUBA certification course from the same shop. Your life is worth the extra expense and you may find you actually enjoy cleaning your boat's hull once it becomes easy.

[fstbttms]

I agreed with every word this guy wrote until I got to this:

Originally Posted by Nani Kai

A Hookah rig will work but they are expensive and also carry their own set of safety concerns. SCUBA is where you want to be.

Hookah has many advantages over SCUBA, especially if the only reason to be able to breath underwater is boat maintenance.

1.- It is inexpensive. Yes, you can spend a couple of grand on hookah rig if you like. Or you can assemble one of your own that is every bit as safe and durable as anything you can buy commericially. And you can do it for a fraction of the price.

2.- An electric or battery-powered hookah will have a smaller footprint and much less weight than tanks, a BC and all the other toys that recreational divers seem to love. It will also be much quicker to set up and use.

3.- With hookah, no trips to the LDS for air refills and no running out of air in the middle of the job.

4.- If you plug a 110-volt hookah into shorepower, it's unlimited free air.

I could go on and on. The only real advantage SCUBA has over hookah is that your ability to swim distances is not limited by an air hose. And of course, this is not an issue when referring to in-water hull cleaning.

[denverd0n]

Originally Posted by OrangeCrush

...if the hose was able to resist being crushed, would the air inside even be compressed?

If you are more than two feet under the water, and you are breathing air, then it MUST be compressed! It will become compressed as it is pushed down to you. There is no way around that, and having the end of the snorkel open makes absolutely no difference to this.

A lot of people seem to have trouble grasping this, but if you are breathing underwater, and you are not breathing through a snorkel tube that is open to the surface, then you ARE breathing compressed air. (And, of course, a snorkel tube that is open to the surface is useless more than 2-3 feet down.)

[fstbttms]

Originally Posted by Offshore454

When I mentioned contaminated air from a compressor that wasn't built to supply air for breathing...

There are no compressors built to supply breathing air. That is a misconception. Any hookah you can buy or build is based on a compressor that was designed to do something else.

[a64pilot]

Originally Posted by fstbttms

There are no compressors built to supply breathing air. That is a misconception. Any hookah you can buy or build is based on a compressor that was designed to do something else.

I didn't know that, I assumed Bauer or someone built a Hooka compressor meant just for that.
If you don't want to go with a compressor, don't have a means to power it etc., a long hose on a tank works just as well and doesn't bother the neighbors

[OrangeCrush]

Originally Posted by denverd0n

A lot of people seem to have trouble grasping this, but if you are breathing underwater, and you are not breathing through a snorkel tube that is open to the surface, then you ARE breathing compressed air.

Yeah you could count me as one of these people. Just for the sake of argument, imagine you have a rigid metal pipe in a u-shape and you push the bend underwater. Where would the force be coming from to compress the air in the bend of the pipe? The weight of Earth's atmosphere is the same, and the weight of the water cannot exert its force on the air in the tube because it's rigid. The air should circulate freely through this passage. I cannot quite understand why forcing it down this tube would entail compressing it, regardless of where it is relative to the surface of the water.

Now, I completely understand that the weight of the water on your chest would make it nearly impossible to take breath down there. And if you could manage to take a breath, I imagine that the air in your lungs would indeed be compressed. And if you took the tube deep enough it would crush your chest or windpipe and eventually force water back up the tube. But the idea that the air becomes gradually compressed on its way down an open rigid tube doesn't quite seem right....

Don't get me wrong, I'm not trying to defend my hair-brained idea. I'm completely on board with everything that Nani-Kai and others said about all the reasons it wouldn't work.

I do have PADI certification and maybe someday I will buy some used gear and clean my hull that way, or possibly consider a hookah system. Both these involve a lot of bulky gear that I would rather not keep on board, so the idea of a cheap homemade pump system was intriguing, but it was obviously just a "pipe dream." For now, I will have to just clean my ablative paint the old fashioned way by going out sailing.

[chris mac]

Originally Posted by OrangeCrush

Yeah you could count me as one of these people. Just for the sake of argument, imagine you have a rigid metal pipe in a u-shape and you push the bend underwater. Where would the force be coming from to compress the air in the bend of the pipe? The weight of Earth's atmosphere is the same, and the weight of the water cannot exert its force on the air in the tube because it's rigid. The air should circulate freely through this passage. I cannot quite understand why forcing it down this tube would entail compressing it, regardless of where it is relative to the surface of the water.

Now, I completely understand that the weight of the water on your chest would make it nearly impossible to take breath down there. And if you could manage to take a breath, I imagine that the air in your lungs would indeed be compressed. And if you took the tube deep enough it would crush your chest or windpipe and eventually force water back up the tube. But the idea that the air becomes gradually compressed on its way down an open rigid tube doesn't quite seem right....

Don't get me wrong, I'm not trying to defend my hair-brained idea. I'm completely on board with everything that Nani-Kai and others said about all the reasons it wouldn't work.

I do have PADI certification and maybe someday I will buy some used gear and clean my hull that way, or possibly consider a hookah system. Both these involve a lot of bulky gear that I would rather not keep on board, so the idea of a cheap homemade pump system was intriguing, but it was obviously just a "pipe dream." For now, I will have to just clean my ablative paint the old fashioned way by going out sailing.

Think of it in terms of a scuba tank. It is closed, and rigid. Yet at 33 feet you have half the air as at surface.
The weight of the water does exert pressure on a closed pocket of air. Your choice of the word "force" when pushing the pipe with air in the tube is accurate. Having to "force" it underwater is causing the compression of the air.
Pushing or forcing air anywhere it doesn't want to naturally be, is compressing it