I looked into them a couple of years ago before I got my dive instructor cert. Like Ssullivan stated they run off a compressor (commonly) or sometimes just off a 80cf tank floating on the surface in an intertube.
They are very good for shallow dives ~30-40 feet. The drawback is you are tethered to a compressor. Some of them are 'portable' ie they float in basically a large intertube and run off a gasoline compressor. To get deeper than 40 feet you need to be pretty much right below the compressor. This can be an issue in a current
as it tend to trail the compressor out behind you at an angle. Most hooka systems are limited to 60' deep and if you have both regs that deep (40'+)they have a tendancy to get difficult to breath due to the demand on the system. Also people with a 'portable' compressor have a tendancy to wander away from the boat they are living on as they get caught up with what behind every coral head
they see and wind
up with a long surface swim back to boat. Not a lot of fun if your just out to play around on a cruise
They are also prone togetting the hose caught or tangled in coral
( bad for the reef) or other structures even though the hoses have a general tendancy to float. Not that this is a serious issue because the hose is pretty tough and you will notice right away due to the tugging on the reg in your mouth. Alternatively, you can wear a belt and run the hose under the belt in the small of your back and then over your right shoulder to you mouth. This helps with eliminating the need to clench down with your teeth on the mouth peice to keep it in your mouth. ( Ssullivan - you will need to keep a regular supply of mouth pieces with large bitewings as your future customers will have a tendancy to bite right through them during a dive. It's an unconcous stress thing, I replace mouth peices on regulators students use on an average of twice a summer .)
I have heard people say that you can't get the bends from diving on hooka, but this is a misconception. You can get bent or 'the bends' technically known as decompression syndrome or DCS at any depth
. The good news is that the shallower you are the longer it takes to get bent.
SSullivan - you are legally responsible for the health
of potential customers who use your hooka system so you need to be aware of the DCS limits. The good news is that since water transfers heat 25 times faster than air most of your customers will be to cold after a hour underwater to want to get back in till much later in the day or the following day. This is a good thing as it helps protect you.
From the PADI Table for a no decompression single
upto and including 35' deep = 205 minutes
35-40' deep = 140 minutes
40-50' deep = 80 minutes
50-60' deep = 55 minutes
From the SSI Dive tables for a no decompression single
upto and including 10' deep = 300 minutes
10'-15' deep = 350 ( I don't know why it's more)
15'-20' deep = 325 minutes
20'-25' deep = 245 minutes
25'-30' deep = 205 minutes
30'-35' deep = 160 minutes
35-40' deep = 130 minutes
40-50' deep = 70 minutes
50-60' deep = 50 minutes
The tables are mathmatical guesses using a formula with several 'guestimate' constants that help define the safe amount of time underwater at any given depth
. They assume that a diver dives to the given max depth and stays there for the entire time. You will notice that most of these are over an hour (60 minutes) long. I think that you will also find ( to the Hooka companies credit) that a given supply of fuel
or air will last no more than 60 minutes which means that for all except the most crazy people diving by themselves ( which you should never allow) they will probably be ok on the time limit.
Ssullivan - Realistically this is probably a pretty good item for your charter
business as it allows for a significant ammount of time for customers to have fun underwater. It limits them to a reasonably safe range of depth which they will explore on thier own and compensate for and by the time time they need to be getting out of the water for safety
reasons they are usually cold and ready to get out, thirsty and ready to get out, or just run out of air (gasoline or empty tank). I would advise that you keep a close eye to be ready to retrieve tired customers by dingy fairly quickly. If you really want to be snazzy purchase
a pair of small wrist mount dive computers
and make sure that the customers watch the no decompression limit time left on the face of the computer. They shouldn't have a problem unless they spend a lot of time in the 50-60 range. This will also provide that little extra information for when they go home that they can brag 'I went to 50 feet!' It makes for good stories to friends and coworkers who don't dive.
I highly suggest that you take the chance to get scuba certified so you can explain how to clear a mask, retrieve a regulator
, and clear your ears to your future customers because I will guaruntee you will get those questions.
Lastly, Like scuba diving, the air on a hooka system will be very dry and have a tendancy to dehydrate people who use it. You should have a standard operating rule
that after they get back to the boat everyone needs to drink at least one full glass of water or juice to help rehydrate them. It's a small thing that they will very likely be willing to go along with if you explain the background reasons to them. Water first, then beer