Doom and Gloom, and how I did it!
Wow, that thread was full of doom and gloom.(See link for aforementioned thread) In my humble opinion, it is not that dangerous to shallow dive on even an homemade hookah. I am sure that my SCUBA training has helped me to be safer with a hookah, but many people I know hookah dive their bottoms all the time without certification. That thread, though, does make some good points. 1) Depth. Dive charts do not even give a recommended bottom time for 10' (as deep as a hull cleaner would ever need to go) so you could spend several hours at hull depth with little threat of 'the bends'. A quick trip to the bottom to check on an anchor would be OK too, just don't spend much time at any greater depth without knowing and understanding a dive chart. 2) Clean air. Use an oil free compressor and have good filtration, also don't use a gauge that may have oil in it. One point I often see overlooked is the hose that you use. Regular air hose can poison you by outgassing (i.e. new car smell is actually toxic), food grade hose is the stuff to use. I'd use an electric compressor far from any sources of exhaust to make sure it is sending clean air to you. 3) Exhale while ascending. It is not necessarily common sense and was thus pounded into us in our intro SCUBA classes. Air expands as you ascend and if you are holding your breath it could damage your lungs. 4) Dive in a safe environment. Always have a direct escape to the surface in case your homemade (or commercial) hookah screws up. Do not dive under obstacles and always stay clear of the hose. Easier said than done, but with care and patience you can keep the hose away from you. That being said, here's how I made one. I bought a 12 volt Thomas Industries air compressor on eBay, used a couple of filters from Home Depot, had a hose made by a local hose supply shop (they do it all the time and have the properly threaded fittings for the dive attachments), found a working second stage regulator (the mouth part) at a garage sale, and screwed them all together. The output of the compressor was set to 100psi, roughly in the range of a first stage dive regulator. (I believe that the commercial hookahs run 40-60psi and must use special second stage regulators with different internal springs.) My total cost was about $150. It worked great for dozens of cleanings and I even did a bit of exploration by mounting it in my kayak, but eventually my little compressor's motor died. Now that I have a fill card at my local dive shop, I just screw my hose (adaptor needed) to my first stage regulator and use an air tank in the cockpit. Disclaimer: Getting certified in SCUBA will make your hookah experience safer and you will feel more comfortable with the equipment and with your actions underwater. Commercial rigs, though very expensive, might be more reliable than cobbled together rigs out of used parts. Please don't sue me if you do something stupid...
