Why are jacket style BCD's the most common??

[Lorenzoid]

So it is marketing, I was not trying to rehash the jacket vs bpw debate just wondering why we see so many jackets.

So from the comments from the historians here, I would summarize it as a combination of historical inertia, marketability, and continued preferences for rental fleet and training use. I really learned something here about the history. I had thought it was mainly the marketability, but it seems that's just one factor. Thanks for asking the question!

 

[MichaelMc]

People live their lives vertical, for the most part, and the jacket brings that into the water. It may not be optimal for specialized diving, but gives a more familiar experience to many.

On a jacket BC giving a more familiar experience, I don't think we want them diving vertically for very long. It seems that current standards promote OW students to become comfortable and proficient horizontal underwater for their pool dives. And that 'swimming' vertically underwater is viewed as endangering the environment, when it occurs close to the bottom.

On the surface, vertical is certainly preferred for breathing. But current dive training seems focused on moving them past that underwater. I would not class diving horizontally as specialized, though clearly things like wreck, cave, etc would be. I'm not sure which you meant as specialized.

 

[jadairiii]

I fully credit GUE/DIR for introducing (or re-introducing) the BP/W concept back into the public eye. ....

Especially for recreational diving. Up until I drifted into Tech diving in 94' I almost never saw anyone diving a wing. I would always get a question or 2 when on a dive boat about my At-Pac by other divers. That said, in 1982 when I was at UF (79-83) my instructor used a Sequest wing for recreational diving. He was also a cave diver but did not use a wing then, he had a Seatec "pillow" bc for cave. Cant even imagine how hard it would be to balance a set of 104's on a chest mounted pillow bc!

Yes kids, a pillow BC, not sure if that is the correct term though?

 

[lowwall]

“Why are jackets the most common?”

As soon as Scubapro came out with the stab jacket it took off like a California wildfire. All the companies followed suit so they wouldn’t get left in the dust. The Jacket BC was one of the biggest breakthroughs of all time and opened up diving to a entire new market that would have been reluctant to take up diving before then when it was backpacks and crude BC devices or no BC devices at all. ...

SCUBA equipment was initially skin diving equipment with a tank on a harness and a reg. There was no flotation component at all. When air bladders were introduced, they were worn on the front and meant to be used for emergency ascents or for emergency flotation at the surface. They were commonly inflated by a CO2 cartridge.

Buoyancy compensation appeared in the 60s in forms that look a cheap life vest, but had a dump valve and some way to add air underwater. These "horse collar" BCDs were not integrated with the tank harness, you put them on first and they had their own straps. Again they were mostly thought of as lifesaving and surface flotation devices because, as in skin diving, proper weighting was considered to be of paramount importance so there was little need for buoyancy compensation underwater.

Horse Collar BCD from Buoyancy compensator (diving) - Wikipedia

In the 60s and early 70s, there was some experimentation with backmounting and integrating the BCD with the harness, most notably Scubapro's BCP (see pic below). But the "experts" of the day considered these to be essentially suicide since they would float you face down at the surface unlike a "proper" front mount BCD. You can see why Scubapro's Stab Jacket was such a hit when it came out. It really did make donning and doffing faster and simpler and it avoided the perceived problem of purely backmounted air cells. Once this came out, all the major manufacturers scrambled to make their own versions. Since Scubapro had a patent on their basic design, the result was an immediate proliferation of jacket types.

The Stab jacket actually predates the BP/W. The backplate we use today was invented by a cave diver named Greg Flanagan in 1979. In his own words from https://asiakas.kotisivukone.com/files/sammakkomies.kotisivukone.com/diverite_39.pdf :

"For those "new" to cave diving, a belly-bag was essentially a horse collar type chest mounted BC
without the collar. The diver, while swimming horizontally, lay on the buoyancy pillow created
by the belly-bag in order to keep his feet up and off the cave floor. However, the weight of the
heavy back-mounted tanks, separated from this buoyancy pillow by the diver's torso,
necessitated the diver to constantly perform a balancing act to avoid being flipped over. This
aspect of their use, coupled with the belly-bag's separate harness system, did not make for a very
comfortable, stable or user friendly rig.

A few people, myself included, had tried the then new Scuba Pro Stabilizing Jackets with
doubles. These were much easier to dive but they lacked adequate attachment points for light
canisters, reels, and other gear. The only back-mounted BC's of the day, At-Pacs and Scuba Pro
BCPs, used a conventional injection molded plastic single tank backpack in conjunction with
"bridged bands", which were only available for 72s and 80s. The injection molded backpacks
needlessly raised the tanks high off of the back and were very uncomfortable. Nevertheless, I
realized that a back-mounted BC offered several major advantages; a clean chest with an infinite
number of gear attachment points on the harness, and natural balance, due to the diver's center of
gravity, i.e. his tanks, being surrounded by the center of buoyancy , i.e. the BC wings. As such, I
set out to find a way to have the advantages of the back mounted wings without the molded back
pack. To do this the harness had to be detachable from the BC and the BC detachable from the
tanks. I concluded that what was needed was a thin strong metal backplate (with attached
harness) which would sandwich the BC between the plate and the tanks, without adding
appreciably to the profile of the rig.

I made my first back plate in early 1979 from a surplus aluminum road sign of unknown alloy. I
traced the outline from the solid center section of the Scuba Pro BCP onto a paper stencil and
transferred this onto the aluminum. I next cut out the aluminum and had a single parallel set of
bends, about 2" apart, made in the center of the plate, running from top to bottom, forming a sort
of flat bottomed "V", into which I drilled two holes (one top/one bottom), which were used to
bolt the plate to extended studs on a set of bands on double 72s. I then proceeded to beat the
aluminum around the curvature of the tanks with a sledge hammer, soon discovering that
aluminum alloy is pretty tough material, taking several hours to conform the aluminum to the
tanks. The webbing off a Navy harness was then attached through a series of slots cut in the
metal and the first back plate was born. I used this first back plate on both Double 72s and
Double 80s throughout the rest of Sheck's cave course with awesome results. Balance was so
easy and my cave diving technique was so improved that I became the envy of my classmates
who continued to struggle with their belly-bags."

Flanagan hand made plates for other cave divers until Dive Rite started producing them commercially in 1984. By which time the jacket BCD was firmly entrenched in the recreational diving world.

The inner side of the ScubaPro BCP. Shape looks like a Freedom Plate, a good example of convergent evolution

Note: image is a screen grab from

 

[lowwall]

The horsecollar BC was much better than crude. It was sometimes inconvient because of its placement and it would float you on your back when inflated, good when unconscious, but sometimes a pain, but no worse than a BP/W. I went to a stab jacket for a couple of decades, but only lasted 5 years, 'till I got the cash togather, with a poodle jacket.



The poodle jacket was an evolution of the stab jacket as it became tighter around the waist, and body, with the use of elastic, Velcro, and the cummerbund. Earlier jacket BCs had and needed a crotch strap, and were a bit different animal than what one sees now.

People live their lives vertical, for the most part, and the jacket brings that into the water. It may not be optimal for specialized diving, but gives a more familiar experience to many.

Bob

I was hoping someone would chime in who had dived all of these variations. I wrote these because I enjoy research (I was a university librarian before I went to work for my wife's law firm), but haven't dived anything but jackets and a BP/W.

 

[Miyaru]

Backplate and wings are the worst equipment a shop can sell.

Once you sell a backplate to a customer, you know he's not coming back to replace it for the next decade. Because that piece of metal is never gonna break.
Same goes for the webbing, I got a backplate with webbing from 2011 and over 3000 dives later, the damn thing is still not worn down.
But even if the webbing was to be replaced, it costs too little.
And wings....even worse. In case of a puncture, the diver could open the zipper and fix the bladder. Another customer that won't be coming back for a replacement.


Jacket style BCD's have so many advantages. First of all, they come in all price ranges. There's always a more expensive jacket to sell, so that's more profit. And while BP/W are totally boring from a sales point of view, there's so much to tell about all the extra options of a jacket!

It's got pockets, to stash your divelight, SMB, spool, camera, whistle (did you buy all of these yet?), it's got integrated weightpockets so you can finally get rid of that uncomfortable weightbelt! And......it has got more D-rings. More is better. Now you can attach all your accessories to your BCD and to do that, we not only have this marvellous range of plastic clips, we also have, for just a few bucks extra, these amazing lanyards! So never any worries again that your compass, divelight or camera disappears into the dark depths.

Oh you're shopping for a dive center? We have every size you could possibly ever need! Ranging from XXS, XS, S, M, ML, L, XL and XXL! Yes I know you could adjust the webbing of a backplate to exactly what the diver needs, but think of all the precious time that the instructor or divemaster would waste, adjusting harnasses! Soo much easier to just grab the right size for your diver off your equipment rack.

I see you're looking at that backplate. Don't! As you can see, all that metal on your back can only be totally uncomfortable. And even worse: at the surface, after inflating the wing, it will push you over, face-down in the water and that's panic waiting to happen.
No this jacket is absolutely the best you can get right now! It will last for the years to come!

 

[jadairiii]

The only back-mounted BC's of the day, At-Pacs and Scuba Pro
BCPs, used a conventional injection molded plastic single tank backpack in conjunction with
"bridged bands", which were only available for 72s and 80s. The injection molded backpacks
needlessly raised the tanks high off of the back and were very uncomfortable.

That was a MAJOR drawback with the At-Pac was the weight box that put the tank(s) at least 3 to 4 inches farther from your back, and doubles were worse. Diving doubles with an At-Pac those buggers continually wanted to roll you.

Also of note, double tank bands for singles are common now, and real early back packs had them (real early) but it was the At-Pac that first had, what you could consider modern, double stainless steel cam bands and you didnt need any rubber insert to keep the tank from sliding through.

I will make one other comment, with the SP BCP, that single steel band was a bitch to get tight enough to keep from having your steel 72 slide through it. It was at least a year or two after I had one that Scubapro sold the rubber insert, which helped a ton.

 

[BRT]

You're not going to hear this often here, but if you're going to be bobbing in waves (for example, shore diving) then you're likely to be more comfortable in a jacket. Seeing as you'll be more vertical. If that's your main diving environment, then before you listen to someone who tells you that back mount works just as well at floating you vertically, try one first before buying!

I certified in a back mount setup and never looked back after I got a regular BCD. Much nicer on the surface.

 

[Jcp2]

The original plastic backplate without bladder still exists as the skeleton of many BC jackets.

 

[Eric Sedletzky]

The original plastic backplate without bladder still exists as the skeleton of many BC jackets.

That’s very true.