Never heard of it.
TrueTexan, the question you ask is quite complicated. Until the early 70's most divers did not use BC's even though, in 1957, USD briefly offered a small CO2 life vest, today commonly called "horsecollar". There was little market for it however. The only other option for 50's divers was a device the size of a pack of cigarettes called a "res-Q-Pak". The pack contained a CO2 inflatable water wings. Squeezing the pack caused it to inflate. It was held to the waist belt with a clip.
After this came the Swimmaster "Lifegard" life belt which was a horizontally mounted rubber balloon with two CO2 detonators, one in each end. The balloon was clipped to a thin web belt fastened around the waist with D rings. A few years after the appearance, and disappearance, of this putative lifesaving device new trends began to assert themselves in our lives. Auto seatbelts became standard equipment and the book "Unsafe At Any Speed" was published. Safety was becoming a hot button issue. The younger generation of American men began to slowly accept the idea that it was not "sissy" to wear a flotation device. This trend was accellerated by the "institutionalization" of diving. Where the sport had once been loosely organized by many small diving clubs, there now appeared new types of teaching/marketing groups which held to formalized agendas and characterised themselves as "certification agencies".
By 1968, two types of vest had come into vogue. USD, Dacor, SP and Stebco were selling versions very similar to the 50's era lifejacket. They were compact horsecollars with CO2 detonators and small mouth tubes. The USD vest was innovative in that the mouth tube also acted as a simple overpressure valve. Most users probably did not know this however. Also, during this time the military UDT lifejacket with twin detonators, separate overpressure valve and small mouthtube were beginning to appear on the civilian market. It was said that the twin 25 gram cartridges could raise a diver from 200 feet. Normally, such vests were inflated orally and CO2 was held as an emergency measure. Ordinarily, vests were only inflated to raise a heavy load or in emergency. Buoyancy control was not a design function and this was dealt with in other ways.
In 1972, there was a company called Seatec which began manufacturing various types of adapters, both for lifejackets and regulator first stages. The regulator adapters allowed multiple LP hoses to be screwed into the regulator. The vest adapters permitted the CO2 detonator to be removed and replaced by a device which was in fact an LP valve, had a trigger and fitting for a low pressure hose. Thus, the vest could be filled directly from the tank, the first such device that I am aware of. By 1973, competing but expensive BC's (the term was just coming into use) from the French Fenzy Co and USD came on the scene. The Fenzy consisted of a heavy duty horsecollar vest with a LARGE mouth hose and an attached HP bottle. The vest was inflated by turning a knob on the tank or using mouth inflation. Also, USD presented a large capacity horsecollar using an inner cell and outer fabric, with a CO2 detonator, a large mouth inflator hose, and a button operated LP inflator valve mounted on the right front of the vest. Two of the most important features of these vests were the crotch strap and overpressure valve which signalled that these models were now more than life jackets but could be employed as a practical means of buoyancy control.
(II)
As the year 1973 was in swing there appeared a back inflated BC called the Atpac. This was followed by Waterlung, Scubapro and Seatec's version in 1973-74. In appearance and function these vests can be visualized by looking at a picture of the Halcyon Pioneer or Explorer. However, instead of a metal backplate, the Atpac, etc employed a full plastic backpac of the type that was normally used for carrying bare tanks. Simultaneously, Seatec, Scubapro and Waterlung invented a new type of LP inflator which was mounted inline with the oral inflation hose. So, by this time, the principal competitors were USD with the horsecollar and vest mounted inflator, Scubapro with a unique single cell horsecollar and hose mounted inflator, Atpac with a back inflate BC, and Seatec and Waterlung which offered horsecollars and back mounts, all with hose mounted inflators of their own design. Healthways marketed a light, single cell horsecollar with Seatec inflator. Not to forget Dacor in all this. They were producing a double bag horsecollar similar to the Seatec and, like all double bags, renowned for trapping air between the cells. They also introduced a hard shell, back mount BC with integrated weights. The best way to visualize this is to look at a turtle shell. It died rather swiftly.
(III)
The early 70's were an exciting and competitive time for BC designers. Controversies waxed large over the relative merits of the exciting new Atpac and the vastly updated horsecollar style BC. Despite the reported advantages of the back mount there remained a substantial following among those who respected the surface flotation capability of the collar. Meanwhile, improvements of an incremental nature continued, such as pockets, and a short string which converted the overpressure valve into a combined "dump" valve. However, the revolution was far from over and soon the industry was to be shaken by a new invention which would cause the collar to disappear and the back wing to diminish into obscurity.
In the summer of 1977, Scubapro introduced a completely new type BC. This had been the invention of a retired airline pilot who arrived at the concept while tinkering in his garage. After failing to sell the idea to USD he approached Scubapro who bought the patent rights. This BC incorporated most of the earlier buoyancy control devices such as inline hose inflator, etc. However, the shape and fit of the single cell fabric was entirely different. This BC fit the upper torso like a traditional gentleman's vest. The aircell was a continuous flow type which afforded outstanding buoyancy distribution and trim. The fit and cut was such that the BC was almost completely unobtrusive in use. Like the Atpac, it also used a full plastic backpac with SS adjustable tank band, but unlike the Atpac, used only a single web waist belt as the diver's arms fit through the jacket itself. Like the old horsecollar, the SP jacket afforded full upright surface flotation. It had one flaw, adjustability. Since the shoulder and arm size were determined by the cut of the BC's fabric, one could not dive naked with a jacket which was sized for a fully clad diver and vice versa. Therefore, this posed a problem for traveling divers. However, for some divers, these vests were much faster and more comfortable inasmuch as three straps were eliminated. As far as the CO2 device, Scubapro continued to include fittings for these but the detonators had to be special ordered. Basically, the CO2 era was over.
(IV)
Within a year it became apparent to the industry that the new flotation jacket which USD had scoffed at was going to take market share from them all. US Divers, as the market leader, was in a bad position being faced with the problem of dealing with the Scubapro patent. They determined that a key feature of the patent was the flow through principle; that is, the air cell is a continuous loop from top to bottom and side to side. Their solution to this obstacle was to design a jacket which blocked off air flow at the shoulders and thus avoided infringement of the patent. The section from shoulder to waist was cut away, sealed off and replaced by a strap. Of course, the strap had an adjustment buckle and this was touted as an "advanced" concept. Unfortunately, the potential benefits of an adjustment at the shoulder were lost because the shoulder strap did not form a continuous loop with the backpac such as did the straps on the original plastic pacs commonly fitted to a tank. Instead, the USD jacket strap design dead ended at the top and lower end of the jacket which made it difficult to tighten down the jacket without squeezing the diver, raising the tank, or running out of adjustment. As I said, Scubapro's design did not allow this either but the SP jacket controlled ride up by including a precise fit with rather small arm holes and so did not depend on any further adjustment to prevent shifting of the SCUBA tank. The upshot was that the USD and other competing designs did suffer from ride up which really could only be solved with a crotch strap. These were rarely used for reason of convenience and were not standard equipment. The Scubapro did not require a crotch strap but retained stability only if the fit was near perfect and the arm holes, in particular, fit snugly. As the year 1980 dawned, the evolution of the BCD had finally taken a clear path with new, competing designs of jacket style BCD's, the horsecollar rapidly disappearing, and wings struggling to avoid extinction. The inline hose LP inflator design invented by Seatec was beginning to win out over competing designs, with Scubapro and USD as the last hold outs. Soon, the USD vest mounted LP inflator would disappear along with their horsecollar, and both companies would eventually adopt the Seatec inflator quick connect design.
(V)
During the 1980's, many companies, new and old, got into the business of making more diverse diving equipment. However, changes were mostly incremental and of a marketing nature. It seemed as if the basic form and function of SCUBA gear had arrived and it was only necessary to work out the details. Scubapro immediately began to tinker with the new "stab" jacket BC design. In 1979, they added a pocket which was sized to hold the SP Decompression (DCP) Meter. During the coming decade, they added more pockets, made the skirt longer(the next generation of men were bigger), and revised the back pac. Also, the expensive, adjustable SS tank band was replaced by a synthetic fabric with a new type of SS adjustment clamp. Later, SP offered a unique octopus regulator which fitted inline with the BC inflation hose.
The other companies were busy touting their double bag designs, multiple pockets, adjustable straps and mega air lift. They modified the back plates and eliminated stainless steel bands and clamps in lieu of fabric and plastic composite adjustable tank buckles. By the late 80's additional, bottom mounted dump valves were an option. Companies tried to make their vests more comfortable by adding "cumberbunds" and smaller buckles made from the new high tech plastics. Meanwhile, as the 80's came to a close, some companies, like Seaquest, were taking another look at vest fundamentals such as single cell/double cell construction, and alternatives to the basic jacket form and even the back inflate concept.
In fact, the industry had not heard the last of the bat wing. In the "wings" new ideas were brewing, and the dive equipment companies were starting to listen.
(to be continued)
