Hello Makahaman, I asked my hubby how to explain the type of hookah we use as he's the one who built it! I merely use it! Here goes:
My name is Garry, and like yourself have been using scuba for over 30 years. I've also used different types of hookahs, gas (petrol) hookahs and now started using an electric hookah. I've always made my own. My first experience with hookah was one that I used to use on my gold dredge with an Eldorado diaphram with a small Honda motor. Because my diving was relatively shallow in rivers it performed perfectly. But I was always aware of the fumes and always had the air intake away from the exhaust. My second hookah was a little more serious, a twin piston Clisby with a Briggs and Stratton motor, but being an oil lubricated compressor, I had to run activated carbon scrubbers. I could run two divers very comfortably at over 60 feet depth. But one year I had broken one of the scrubber filters without being aware of it and we ended up being very sick after a dive of 1.5 hours at 45 feet depth, which in turn made me go back towards oilless compressors. For the next 10 years I stuck to my scuba until 3 years ago I made another hookah with a Thomas diaphram compressor with a Briggs and Stratton motor which provided many hours of enjoyable diving though the fuel tank would only last 1.5 hours. Changing the motor to a small Honda may have got more bottom time because they are a little more economical. The problem with the petrol (gas) is that when you are detecting, you are always in public places because that's where the targets are. So getting on the internet and reading about electric hookahs I thought this would be a practical solution to the noise problem, because I didn't want to draw attention to myself while diving.
I ended up making my own electric hookah, though this one may be a bit of an over design for what we want. I can run 3 divers at over 30 feet, but with two divers, last weekend my wife and I got 3.5 hours diving out of the batteries. The only problem with that is, to charge the batteries up I have to find somewhere to stop where there's power, and they need to charge for over 10 hours. No diving or buy extra batteries which are quite expensive. With a petrol hookah there's none of this problem. But you do need to come up on a regular basis and refill and you do have the noise which can irritate other people in public places.
So which one is best, electric or petrol? It really depends on your application and where you are likely to go detecting. In a public place I love the electric. A flick of the switch and forget about it until there's no more air. The advantage of petrol hookaks is that you don't have to worry about battery charging, just refill whenever you want, but sometimes with salt saturated air, it can cause a petrol one to be hard to start.
Have a look on the net, punch in electric hookahs, and you will get a lot of sites to look at. or punch in Keene Engineering as they make an electric hookah for a reasonable price. Keep in mind, many of the comercial ones may not give you the bottom time because they use either 24 - 35 amp batteries which have a great advantage in being a lot lighter than the unit that I've made, and are easier to carry down to the water on your own.
Hope this was useful to you, regards Garry (via Golden!)
