Electric the 110 volt AC ones are good for using at a dock or on a yacht to clean the bottom. The battery ones are a joke. It will use a car battery down very quickly. They used the 12 volt Gast pumps on GMC motorhomes to inflate the rear airbags in the suspension. They are sometimes available, but they have low CFM, and use a lot of juice. I have a 110 volt AC Gast motor with 2 cylinder oilless pump. It the same as the Kenne 110 volt or engine driven pump Gast PCA-10. I think it has 10 CFM which I know from using these, it is more than enough for 3 people, I dont think 4, but maybe if they were just lazing along, not working hard. I bought it to use as a boat cleaning hookah on my yacht, but I have a gasoline powered one, and never used it. If someone needs a 110 volt (plug into the wall or generator, or you could use a big inverter-I dont know how many amps it draws, but can look), I have a perfect running motor with pump attached from the factory. I will sell it for $150 . and you pay shipping. It weighs at least 20 lbs. I have more than that in it. If anybody has an interest, I will take pics and show what the decal says. No hoses have been hooked up to this. I also have the whole PCA-10, with 2 head compressor, and flywheel, crankshaft, fan housing, belt and pulley housing, maybe even a base plate, etc, but heads valve plate(a thin plate made of stainless) has some tiny holes from using it for years around saltwater, and I bought a new one(PCA-10) for $600 or so. The PCA-10 can be fixed, it just needs new valve plates, and gasket set. Otherwise it is fine. It actualy worked fine, but I took heads off and found tiny holes in stainless plates. I would like to get $100 and you pay shipping. I will get pics of that too if any one has any interest. I have a 5 hp honda engine that has the right pulley on it, and cant get the pulley off, I really havent tried hard though. Engine is shot, I think a stuck valve, but you can have that too with the PCA-10, and then have the right pulley. Pm me, Steve.
Ok guy and gals here is a silly question, i have been looking at the hookah systems pretty dang neat setups, have anybody used them?? I'm open water certified to 60 feet, my other question is we didn't cover this in my training or i don't remember does the hookah put the residual nitrogen in your joints and bloodstream like compressed oxygen out of your scuba tanks, being how your air supply is at the surface instead of being on your back and compressed? Thanks. 
Now if my tax refund check will hurry up and get here its gonna be an interesting summer on my area lakes lol.... 
