Evolution of BCD

[ScubaEyeDoc]

One of my OW students was originally certified in 1988 at the age of 12. He went a couple of decades without diving and decided to redo the OW course recently. While introducing the students to the dump valves he made the observation that his BCD in 1988 was absent of a rear dump valve. Does anyone know when the rear dump valve was introduced?

Much thanks for any knowledge you can share with me!

 

[northernone]

Here's one data point.

At home I have a horse collar style bcd from the mid 1960s with a back dump valve. They are pretty common on most bcds from the 80s I've seen. Off hand we have 6 all with back dumps.

Cameron

 

[Akimbo]

Here is an image of the wing that came inside the WaterGill At-Pac in the late 1970s and early 80s -- probably the first commercially available wing. There was only one penetration into the bladder for the elbow. The power inflator, manual dump, and OPV (Over Pressure Valve) was all mounted to the corrugated hose.

The LP hose was routed to the power inflater inside the corrugated hose. Note the LP hose with the QD (Quick Disconnect) that attaches to the chrome plated fitting near the elbow. The first change to this design that I remember was the Seaquest wing with a much larger OPV mounted near the top of the bladder, more or less opposite side the elbow. I don't recall when the manual butt dump was added -- basically and second OPV with a string attached.

 

[Eric Sedletzky]

As far as I know, the bottom dump became pretty much standard (and celebrated) when the modern BP/W and single tank donut wing was invented for use on modern back plates. Prior to that I think any sort of bottom dump is sketchy to find and certainly not consistent throughout different brands and models. I don’t remember there being one on my first back inflate Seaquest BC or any of the other jacket BC’s of the time. And if there was, we definitely were not schooled on their use in any dive training that I recieved, I would have specifically remembered that if there was.
Part of the popularity these days of using bottom dumps is the obsession to stay flat (in trim) throughout the entire dive. Prior to that there was a lot less emphasis on holding position and most people just used the shoulder dump for adjustments.

 

[Akimbo]

To really look at the evolution of the modern BCD you have to begin with the Bouée Fenzy, developed by Maurice Fenzy in the 1960s. Here is an ad from Skin Diver Magazine when it was first imported into the US:

It varied from the Mae West-style horse collar buoyancy devices of the time because it was designed to be inflated at depth. It included a small HP bottle, overpressure valve, and dump valve on a corrugated hose. The bottle was too small to use for buoyancy compensation so was reserved for emergency use only.

It didn't take long for resourceful divers to figure out that you could adapt power inflators made for primitive drysuits of the time so it could be inflated off their back gas. Shortly after that came various Fenzy clones, the WaterGill At-Pac, and the original stabilizer jacket patent by Scubapro.

 

[tursiops]

My UK diving buddies in 1968 had Fenzys and I was much envious.

 

[chrispscott]

As far as I know, the bottom dump became pretty much standard (and celebrated) when the modern BP/W and single tank donut wing was invented for use on modern back plates. Prior to that I think any sort of bottom dump is sketchy to find and certainly not consistent throughout different brands and models. I don’t remember there being one on my first back inflate Seaquest BC or any of the other jacket BC’s of the time. And if there was, we definitely were not schooled on their use in any dive training that I recieved, I would have specifically remembered that if there was.
Part of the popularity these days of using bottom dumps is the obsession to stay flat (in trim) throughout the entire dive. Prior to that there was a lot less emphasis on holding position and most people just used the shoulder dump for adjustments.

Scubapro had lower dumps and shoulder dumps on their jacket BCs by at least the mid-1980s. It's one is the things they marketed to set themselves apart as high end gear.

 

[CT-Rich]

I had an early 1980s Seatec Jacket BC. It came with a right shoulder dump and a CO2 cartridge. You could either orally inflate or use a power inflator. Back then, as was pointed out, there was not a fixation on perfect trim you see today. You were usually dumping gas to submerge or venting gas on ascent. At the time, it would not have occurred to me to need more dumps. But that may have been just me.

The number of dumps is a selling feature, some have more than others. The early jackets and horse collars were light on features becau some of them had just not been thought of yet.

 

[Bob DBF]

I had an early 1980s Seatec Jacket BC.

I was very sad when mine bit the dust, of course it took a couple of decades. Almost indestructible. A few years in poodle jacket hell then got the BP/W.


Bob

 

[Sam Miller III]

@ScubaEyeDoc

"One of my OW students was originally certified in 1988 at the age of 12. He went a couple of decades without diving and decided to redo the OW course recently. While introducing the students to the dump valves he made the observation that his BCD in 1988 was absent of a rear dump valve. Does anyone know when the rear dump valve was introduced?"
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I don't know when the dump valve was introduced abd don't have the time to research the subject to infinity

I do know we made out own in the very beginning of the use of the PFV offered by Sportsways and US Divers