The waters surrounding the island of Tasmania, a state of Australia, are reasonably good for most types of fishing including, game, bottom fishing, and diving.
If you are prepared to venture to the outlying islands in Bass Strait, the body of water that separates Tasmania from mainland Australia, there are still some wonderful pristine areas for diving available. The main problem is that the distance from major population centers is well remote from any scuba tank-filling stations. Consequently, on Westwind ll, my Nordhavn 40, I have adopted the use of hookah diving gear because I have found this type of diving in these waters to be very productive when pursuing large crayfish.
The majority of recreational divers using "air assist" use the scuba system. This system comprises a pressure vessel or tank (usually steel or aluminum), carried by the diver, that contains normal air that has been compressed by around 200 times compared to normal atmospheric pressure. The system has two pressure reducing valves. The first stage lowers the pressure from the tank to around 10 times atmospheric pressure. The second stage regulator delivers air to the diver created by the diver's demand and is dependent upon the depth.
A hookah is defined in Wikipedia as "a single or multi-stemmed (often glass-based) water pipe for smoking." The hookah system used by divers probably derived the name because the lines or hoses connected to the pipe (read compressor, but with a different form of resulting high!) are flexible and connect to a central source. Air is supplied to the diver from the compressor on the surface through an air hose. There are no cumbersome tanks for the diver to carry.
Hookah allows me to venture to remote locations and provisions me with air to enable diving for basically unlimited periods. I can travel to areas that most other amateur divers do not frequent and thereby discover fishing grounds that yield large numbers of big fish. These sorties offshore caused me to progress from flybridge style boats to a long-range trawler. Westwind ll provides a wonderful dive platform.
Diving for crayfish usually requires squeezing into their caves. The smaller the diver, the more crayfish he can catch. When I commenced diving, I soon figured that taking a deep breath, removing my scuba tank, wriggling into a cave, catching a crayfish, then looking for my tank to allow me to resume breathing, was probably not going to result in a long and productive life. I built my first hookah system in 1965 and have never looked back.
When researching potential new fishing locations, on occasion I have spent several hours on the bottom just looking for likely productive fishing grounds. Scuba divers tend to dive on only known, proven, and usually less productive fishing grounds in order to preserve their finite air supply.
Another aspect of hookah diving is, I believe, improved safety especially where there is a lot of boating traffic on the surface. Frequently scallop beds are positioned in high tidal flow areas. Any scuba diver not towing a marker float is basically invisible to surface vessels. Divers swept along by the current into traffic lanes are very susceptible to injury upon surfacing. Hookah divers are tethered to their own vessel, so their position within a few body lengths is known by their support crew, and the flexible, connecting supply hoses that we use are a high-visibility yellow and are reasonably easy for other transiting boats to see.
I started diving with tanks back in the early 1960s. Access to good quality filling stations in Tasmania was extremely limited. At that time commercial diving for abalone was a blooming industry in Tasmania, and coincidentally, is still big business here. The divers would travel on motherships for several days at a time and dive for several hours per day. Because the variety of abalone available tended to be in around 10 to 100 feet of depth, the commercial divers mostly gravitated toward using hookah systems. Abalone divers usually stayed on the bottom for a few hours each dive, and sent their catch to the surface using balloons that the divers filled using their own air.
The main improvement to hookah systems during the past few decades has been to the air filtration. Early days had us packing toilet paper rolls into canisters, but today commercially available charcoal filters and water separators provide good results. The photographic evidence shown here of successful recent allowable bag limits of crayfish and scallops illustrate the flexible use of the system. Diving is the only legal method for amateurs to take abalone and scallops in Tasmanian waters.
In the schematic of a typical system, I have defined the major components. The goal of any good system is to insure that the diver is breathing clean, dry air. Starting in the top left of the schematic, air is sucked in by the compressor through a cellulose strainer. The air is compressed from atmospheric pressure to around 10 atmospheres (140psi). We use a 9CFM (cubic feet per minute) capacity compressor coupled to a 4hp Briggs and Stratton engine. This provides sufficient air for two divers to a depth of 45 feet or one diver to 70 feet. The air then passes through a check or non-return valve, which is installed to make sure that after the system is shut down, the energy stored in the reservoir does not run the system in reverse. An unlikely event, but when it happens, if your fingers are in the wrong place like the vee belt drive, it can cause language that even the professional fishermen smile at.
Following the check valve are two filters in series: first a moisture reduction system, then the final charcoal filter to remove particulate. The system has a reservoir, which in our system forms part of the structural base and carry-handle solution. This reservoir provides some reserve in case the system shuts down when a diver is on the bottom. A shut-down causes the air pressure to the diver to reduce. The diver notices that he has to suck harder on his second stage regulator. I can only add that with around 40 years of hookah experience and possibly three or four emergency ascents, I have never had any decompression problems. However, if you intend to dive deep and long, a much larger reservoir is recommended, and having somebody aboard to signal by tugging your hookah line would be a very smart move.
If you do use gasoline-driven compressors, be careful to insure that the compressor suction point is remote from the engine exhaust. On Westwind ll, I run the system on the upper deck to relocate the noisy exhaust away from passengers and divers, and place the suction line high in the rigging to obtain clear inlet air. If using a compressor with a lubricated crank system, it is important to employ vegetable oil or paraffin. This will remove the potential of the diver having to breathe mineral oil-based fumes, which can be toxic. (Mineral oil fumes don't taste too good either!)
The reason I use gasoline power as opposed to, say, a belt drive off the generator or main engine or even an electric drive, is to provide for portability. The assembly illustrated in figure 6 weighs around 130 lb. and can easily operate from a 13-foot-long tender. This provides the flexibility to dive on several locations in a day without moving the mothership from anchor.
For a productive fishing experience, give hookah a try!