A Brief History of Diving (before 1943)

[scubadada]

Thanks @Akimbo

I was lucky enough to have the opportunity to dive a Mark V in the Key Largo canal while I was taking the hyperbaric course from Dick Rutkowski in 2005. This was an experience that I will never forget. I have a picture around here somewhere but can't currently locate it

 

[Compressor]

Fabulous work by Akimbo. Thank you VERY MUCH.

 

[John C. Ratliff]

Akimbo wrote:

Simone wrote to her father in late 1942 to ask if he knew an engineer experienced with demand regulators. He arranged a meeting with Émile Gagnan, a 42 year old L'Air Liquide engineer working on a regulator to convert gas engines to run on cooking gas. Petroleum products were scarce during the war. Cousteau arranged a furlough and met with Gagnan at his workshop in Paris. The first prototype was tested in the Marne River in January 1943. The regulator was attached to back-mounted cylinders with a single corrugated hose to a mouthpiece with an exhaust valve. It was extremely position sensitive and free-flowed through much of the dive.

The solution was to add a second corrugated hose from the exhaust side of the mouthpiece to the wet-side of the regulator diaphragm to equalize the pressure. A prototype was successfully tested in June of 1943 outside of Toulon on the French Riviera. L'Air Liquide named the invention Aqua-Lung and their lawyers filed for patents.

I have the original patent diagrams, as well as one of the original DA Aqualung regulators. Here are the diagrams and photos:

You can view the full patent, along with explanations, by going to Google Patents and looking up the above patent number. Or, you can click on this link to the Cousteau-Gagnan Aqua Lung Patent.

Here are two views of my Green Label DA Aqua Lung regulator. I have had this regulator on open water dives, and it is not an easy breathing regulator. But it is extremely quiet on inhalation (unlike the USD Mistral). Exhalation is very good as it has remained basically unchanged from this model through the DA Aquamaster and Royal Aquamaster. The duckbill valve has changed for the better, but updated duckbill valves can be used in the original DA Aqua Lung regulator.

Note that since the original yolk is narrow, only a few current valves will accept the DA Aqua Lung regulator.

SeaRat

 

[Compressor]

Thank you SeaRat; I loved the account. I have never breathed a double hose regulator. How is the resistance to inhalation and exhalation. I don't have a rebreather and am very cognizant as the amount of noise my bubbles make. How is the noise?

 

[Akimbo]

I have a picture around here somewhere but can't currently locate it

It will turn up, and please post it here when you find it. Nothing like sharing with several hundred thousand of your close friends.

 

[Akimbo]

@John C. Ratliff

Have you ever seen images or a description of the original prototype regulators Cousteau used on those first test dives? Fabricating a regulator can/housing out of Brass sheet metal and machining valve parts must have been challenging in Nazi occupied Paris. I wonder what product the corrugated hoses were from?

 

[John C. Ratliff]

Yes, I have seen that first regulator. Actually, Cousteau had his first film using this first aqualung, which was much different than the first DA Aqua Lung I show above. It was quite an apparatus, taking two people to transport on the surface. Here's the film:


I have a photo of that first regulator in one of Cousteau's books, and I'll see whether I can find it and scan the image.

SeaRat

 

[John C. Ratliff]

This is what looks like Cousteau's second film, and shows the first unit in more detail. Interestingly, it appears that Cousteau, as the person taking the film, used a regulator as a hookah unit, with a hose to the surface. It may be that during that time, they only had one unit.


John

 

[John C. Ratliff]

Thank you SeaRat; I loved the account. I have never breathed a double hose regulator. How is the resistance to inhalation and exhalation. I don't have a rebreather and am very cognizant as the amount of noise my bubbles make. How is the noise?

There are more than one answer to this question. If you have never used a double-hose regulator, then you cannot understand the amount of noise and water disturbance a single-hose regulator second stage causes. Every breath is a noisy, chaotic scene around your face and ears. In addition, there are vibrations in the water that chase small things (invertebrates and fishes) away.

In contrast, the double hose regulator releases the bubbles behind the diver. In an ideal situation, the double hose is positioned between a diver's shoulder blades, and his whole body buffers the bubble noise, resulting in very little noise from the bubbles. In addition, because the bubbles are often released above the diver's longs, the exhalation is easier than with many single hose regulators. (See the diagram I'm hoping to put into this post.)

But each double hose regulator, upon inhalation, has a pretty good noise associated with the inhalation, and caused by the Venturi effect that most have. This results in a lot of inhalation noise. The U.S. Divers Company's Mistral double hose regulator is notorious for this noise upon inhalation, caused by the extremely efficient venturi nozzle that is pointed directly down the intake hose, which results in extremely easy inhalation too, but noisy. The DA Aqua Lung regulator, U.S. Divers Company's first commercial regulator, has no Venturi, and so is very quiet as a regulator, but harder for inhalation effort. Exhalation effort is the same for both regulators.

SeaRat

 

[Compressor]

Thank John.
At some point it would be wonderful if someone wrote a piece on the evolution of the regulator from double hose to single one. I would do it but do not know the details.