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chronology and typology
regulators CG45
marketed from 1946 to 1955

CG-45 regulator, marketed from 1946 to 1955

The CG45 or the unnamed regulator ...

It was in 1945 that Commander Jacques-Yves Cousteau and engineer Émile Gagnan filed the patent for the COUSTEAU-GAGNAN autonomous diving suit.

It is then a device consisting of a portable compressed air reserve (made up of 1,2 or 3 aluminum bottles) equipped with a demand regulator which is the centerpiece (Photo 1).

To launch its marketing, Air Liquide will create a subsidiary: SARL Spirotechnique, which was created on May 26, 1946.

In addition to this, you need to know more about it.

At the very beginning, the first regulators of the COUSTEAU-GAGNAN autonomous diving suit did not have a manufacturer's plate, the serial number was stamped either on the front pan (for the first), or on the high-pressure body on the following ones and that until the end of 1946.

It was not until 1947 that the first manufacturer's plate appeared, no name, just the following inscription:

In addition to this, you need to know more about it.






6, Rue Cognacq Jay, Paris VII



It was not until 1955 when leaving the Mistral that the regulator was considered to be an element that could not be separated from the rest of the SCUBA. Divers will call it CG45 (abbreviation of Cousteau-Gagnan 1945), a name that will remain until today.


This regulator will be marketed from 1946 to 1955 knowing that in 1955 it will be produced only in a hookah version.

Indeed, the CG45 is the only double-pipe regulator of the brand that can be converted into a hookah and vice versa. All you have to do is remove the first stage mechanism by sealing the hole with a plug provided for this purpose on the membrane side, then replacing the caliper with a low pressure connection where the hookah pipe can be connected.


The typology and chronology of GC45.


I have divided the CG45 into 2 types:

The CG45 with archaic bowl (1946 - 1950) which is the rarest.

The CG45 with standard bowl (1949 -1955) which is the most common.

The typology and chronology of GC45


I divided the CG45 into 2 types  main  :

  • The CG45 says archaic mess tin  (1946–1949) which is the rarest. It is divided into 3 versions  subjected to the development of the regulator between 1946 and 1949:  l es without a nameplate , the large SARL plates  and small SARL plates

  • The CG45 says standard and PRO (1950-1956) bowl which is the most common. We see it appear from the 1950s with the PRO version which is used on the new PHOQUE garment, then from 1951 it is generalized on all models with a  standard version in addition.

The CG45 with an archaic body


The CG45 with archaic body can be recognized by their fine tubing with a diameter of 22 mm and more particularly by that of expiration which is bent at 45 ° ( click on photo 2 ).

The reason is simple: on the first scuba suits the regulator was mounted behind the bottle and this elbow made it possible to bring the hose to the front without bending it ( click on Photo 3 ). Unfortunately this position exposed the regulator to shocks during a fall and even more serious when diving, by subjecting hoses to the rocks or the cutting plates of the wrecks…

This configuration will be quickly abandoned to bring the regulator between the diver and the bottle in order to protect it, no longer requiring to bend the exhalation tubing.

Photo 1
Photo 2
Photo 3

The first CG45 without manufacturer's label.


At first the serial number was stamped directly on the exhalation bowl ( Photo 4 ) and then on the back on the HP body ( Photo 5 ) just next to the yoke, the regulators of this period dates from 1946.

I only know 3 units: the serial number 150, 516 and 568. This variant is therefore very rare. These first regulators were sold with a FERNEZ metal mouthpiece. In photo 6 , the picture presenting the regulator in the 1946 catalog.

Photo 4
Photo 5
Photo 6
Porfolio of N ° 568

The big SARL manufacturer's label


In 1947 appeared the first manufacturer's label called big label SARL.You can see Maurice Fargues a few minutes before his fateful dive of September 17, 1947 preparing his diving suit with his large plate SARL regulator on photo11.

There was probably a transition period alternating regulators with or without a label.

This assumption is based on the fact that I found N ° 537 ( click on photo 7 ) with label and N ° 568 without label but with the serial number stamped on the HP body.


The CG45 with large SARL label is marketed with a large rubber tip produced by GODEL for La Spirotechnique ( Photo 8 ).

Note that the serial number 864 ends with the letter N. It is mounted in hookah therefore can be N for Narguilé who mean hookah in french ....

( Photo 9 and 10 )

This regulator would come from the arsenal of the Orient. We do not know the reason for the presence of this letter, however even if to date it is the only large SARL label known with this feature we can assume that a small series has been marketed.

The biggest serial number of a CG45 large SARL label known to date is N ° 1097 which means that a quantity of about 550/600 units was produced however my research allowed me to find only 11 units all around the world, making it one of the rarest and most sought-after regulators by collectors. In photo 12 , the image presenting the regulator in the 1947 catalog.

Mistral 005 copie.jpg
Photo 7
Photo 10
Photo 8
Maurice Fargues avant sa dernière plongée le 17 septembre 1947
Photo 11
Photo 9
Photo 12

You will find in slideshow the 11 large plaques from private collections that I have found to date around the world: the numbers 537 - 631- 684 - 763 - 835 - 864N - 941 - 969- 970 - 1080 - 1097 ( click for enlarge photos)

The small manufacturer's label SARL


In 1949 (maybe late 1948), the CG45 with small SARL label appeared, it came in 2 variants:


-The one with the archaic body which is still produced but the GODEL rubber mouthpiece is replaced by a straight metal mouthpiece as the Fernez type ( Photo 12).


-The one with the first standard body( Photo 13 ) with a configuration called PRO (professional). It has been specially developed for the brand new constant volume (drysuit) developed by Spirotechnique: the PHOQUE suit ( Photo 14 ).

On this body the tubes have a larger diameter since we go from 22 to 25mm knowing that the expiration is no longer curved. They have threaded connections welded with tin which not only allow to equip the regulator with the famous PRO tip but also to easily dissociate the hoses at the body of the regulator or the mouthpiece which remains attached to the hood .

As of today, the smallest serial number of a known CG45 small label SARL is No. 1137 and the largest No. 1871 , an estimated production of around 750 to 800 units. Despite this I have managed to identify to date only twenty units around the world.

An important detail, the first small labels SARL units were mounted "as a large label",I means vertically, the length of the label perpendicular to the pipes ( Photo 15 ). It was probably only from 1950 (around the serial number 1200) that the labels were fixed horizontally ( Photo 13 ). In photo 16 , the image presenting the regulator in the catalog of 1950.

There are also 2 special cases found to date, the number 516 which I am talking about below and the 583 (Photo 17) . It should be understood that today we are working on hypotheses based on observations because unfortunately the archives of La spirotechnique were destroyed during the move from Levallois to Carros and that all the pioneers of spiro died today.

It would seem that in the years 1948/49, (for me the most probable hypothesis), the La Spirotechnique sold in spare part of the pans assembled with small SARL label by stamping the serial number at the request of its owner. But very quickly this practice would have been abandoned (since 1950) by selling a virgin pan, without label, less restrictive for the after-sales service.

Photo 12
CG45 petite plaque SARL
Photo 15
Photo 13
Photo 16
Photo 14
CG45 petite plaque SARL 001.JPG
Photo 17

Slideshow of some CG45 small SARL labels found in various collections

(click to enlarge the photos) .

CG45 with standard bowl

The small SA manufacturer's label


In 1950, to meet the demand for production of the Cousteau-Gagnan autonomous diving suit, the status of La Spirotechnique changed from SARL to SA.

Appearing a new small manufacturer's label with the mention SA LA SPIROTECHNIQUE.

The manufacture of the archaic body is abandoned in favor of a new variant in parallel with the standard PRO version, which I called the standard version ( Photo 18 and 19 ).

In appearance similar to the PRO it is identified by the absence of the threaded tin connections on the pipes and by a new straight metal mouthpiece shorter than the Fernez type from 1949. This tip will be kept when the regulator comes out. Mistral in 1955 and will be called thereafter "D10 mouthpiece" term taken from the reference of the standard Mistral from the 1962 of La spirotechnique catalog.

To date, I have found CG45 with small SA plate included between serial number N ° 1960 to N ° 6194.

Photo 18
Photo 19

Slideshow of some CG45 in SA label version

(click to enlarge the photos)

These CG45 are divided into 2 groups:


  • The first group consists of regulators with serial numbers stamped with rough numbers (to date including serial numbers N ° 1960 to N ° 5127 )

There are mostly regulators mounted in yoke versions because the hookah versions were produced only on demand for professionals.

There are 2 variants:

  • A series produced in 1951, with at least 230 units bearing a serial number ending with the letter M (from serial number 2542M to 2772M with certainty). The significance is unknown at this time, but probably a series for the Navy. ( Photo 20 and 21)


  • Another variant with at least 177 units of regulators will be produced in 1953 with the label known as “mounted upside down” ( Photo 22 et 23) (from serial number 4166 to 4228 with certainty) This designation comes from the fact that if we rigged the CG45 normally (pipes oriented upwards) the label appears upside down. This is not a factory assembly error as I read on some discussion forums. This series is designed to be rigged down the tubing to increase the protection of the rubber hoses (Maybe for use in caving). Of course by respecting this configuration the label will appear in a correct position. This assembly will even be taken up later by the Spanish manufacturer Nemrod on the black label Snark III regulator (Photo 24).

Photo 20
Photo 21
Photo 22
Photo 23
Photo 24
  • The second group of CG45 with SA label is a last series produced in 1955. It probably consists of 1000 units comprising exclusively CG45 in hookah having the distinction of having a low pressure elbow connection, unlike earlier hookahs which have a connection in the extension of the HP body.

In addition, their serial number is stamped with fine numbers like those used on Mistral regulators from 1957.

This hypothesis is based on my observations made in private collections and museums, ranging from serial number 5206 to 6194 inclusive, knowing that the latter is the largest serial number known to date for a CG45 regulator.

We can therefore assume that the total production of CG45 is around 6,200 units ... How many are left? Difficult to say but as I found 72 currently in private collections after a good ten years of research I think that by being optimistic there should not remain more than 200/250 units around the world.

Slideshow of some late 1955 versions in hookah version

(click to enlarge the photos)

Let's take a look at the special cases now.


We must put ourselves in the context of the time, we are in the beginning of scuba diving and there is no standard yet like today, everything is to be put in place.

The CG45 often underwent modifications according to the experience of its owner.

They could undergo transformations in order to repair it, improve its performance or simply to personalize it.

It should also be understood that the pioneer divers, often made up of former soldiers, were very proudly attached to the serial number of their regulator.

The latter symbolized their hierarchy in the seniority of the divers.

It is probably through this tradition that Spirotechnique has long put forward its serial number on its regulators, as shown on a manufacturer's plate, while its primary function is to enable after-sales monitoring.

This attachment to a small number of series and still relevant today in the world of collectors: for example a Mistral with the address COGNACQ JAY has more sentimental and market value with a 2 or 3 digit serial number than 'with 4… and yet they all date from the production year of 1955.


CG45 with standard bowl without manufacturer's label


The diving tanks at that time had no base and consequently they did not stand alone… causing numerous falls and deformations of the regulator bowls, obliging their owner to change them.

Spirotechnique sold for this purpose in its list of spare parts for bowls ... but without the manufacturer's plate which was just installed on the bowl of the new regulator.

This is the reason why we find a lot of CG45 whose pan of the humid chamber has neither label, nor the 4 small holes of the rivets of a part label.

It is by no means a CG45 called military! They should also not be confused with the archaic CG45 of 1946 which have their serial number engraved on the HP body.

The problem with these CG45 is that they are impossible to date precisely in the absence of the serial number.

Slide show of a CG45 without label

(click to enlarge the photos)

The archaic CG45 without manufacturer's label and without serial number stamped on the HP body.


They are simply former SARL label regulators!

Same as the case mentioned above, following the vagaries of the dives the pan had to be changed.

I only know one copy exhibited at the Dumas museum in Sanary, it is mounted in a hookah ( Photo 24).


The CG45 with large SARL label mounted in standard bowl and PRO configuration.


It is simply an upgrade made by the owner at the time.

In fact, the particularity of the CG45 regulator is that it is convertible and modular:

You can change the rear bowl and the archaic exhalation nozzle against a standard PRO nozzle without worrying about adaptation!

This made it possible to adapt the regulator to use with the constant PHOQUE volume.


The CG45 serial number 516.


Finally, here is probably the most beautiful example showing the complexity to date certain CG45 regulator.

At first glance we are in the presence of a "small SARL label" with an archaic bowl fitted with the rare and mythical FERNEZ mouthpiece from 1946. We can deduce that it dates from 1949 because its plate is fixed vertically "to the big label" , this is how I name the plates which are mounted with the length parallel to the base of the exhalation nozzle, in the manner of large SARL plates.

After 1949 all the small SARL or SA labels found appear horizontal when the regulator is rigged on the block, forming an angle at 45 ° relative to the base of the expiration nozzle.


By observing it more carefully we see that its serial number is 516, which is not logical in the chronology established previously.

Returning the regulator we see that the serial number has been stamped on the base of the HP body.

We are undoubtedly in front of an old CG45 without label  from 1946, hence the Fernez mouthpiece.

What happened to him ? I think that simply its former owner wanted to put a manufacturer label on it. Since the plate is riveted and the serial number is stamped "Spirotechnique"

Upon reflection it is obvious that this modification dates from the beginning of 1949, because probably for a short period Spirotechnique supplied as a spare part the front bowl with a small SARL label by stamping the serial number of the regulator.


Photo 25

Slideshow of CG45 N ° 516

  (click to enlarge the photos)

Restoration of my CG-45 "standard version"
with small SA label
N ° 3783

Disassembly of the block

Reassembly of the block

Second restoration completed on March 8, 2016 with the reception of the bowl part in rechromage on January 28. My CG 45 N ° 3783 has a new look. Ready for new adventures, a bit like the Calypso soon, I hope with all my heart.

I present here the restoration of CG45 N ° 5002 by my friend Stéphane Eyme.

Good job done with passion.

Description of how the CG-45 works

schéma de principe du détendeur CG45

CG-45 block diagram

This regulator allows the supply of sufficient air, which is automatically relaxed in the lungs of the diver.

Its dorsal position ensures maximum respiratory comfort, the membrane being at the level of the bronchi.

It consists of two relaxation floors. The first stage transforms the high pressure into an intermediate pressure (so-called medium pressure) of around 11.5 bars. The second stage supplies on demand air at prevailing ambient pressure at any depth.

Its ease of use effectively eliminates the risk of shortness of breath.

Its design cannot cause a lack of air, its circuit open to expiration, leads bubbles out of the field of vision.

Étant donné que le plus gros numéro de série retrouvé à l'heure d'aujourd'hui est le 6194 on peut donc supposé que la production totale de CG45 s’élève au alentour de 6200 unités… Combien en restent-ils ?  Difficile à dire mais comme j’en ai retrouvé 84 actuellement dans des collections privées après presque une trentaine d’années de recherche je pense qu’en étant optimiste il ne devrait pas en rester plus de 200/250 unités à travers le monde.

Voici la liste des CG45 qui m'a permis d'effectuer ce travail de recherche et d'analyse:

150 no label

516 no label (at the origine)

537 S.A.R.L. large label

568 no label (at the origine)

631 S.A.R.L. large label

651 S.A.R.L. large label

763 S.A.R.L. large label

835 S.A.R.L. large label

864N S.A.R.L. large label

870 S.A.R.L. large label

939 S.A.R.L. large label

941 S.A.R.L. large label

970 S.A.R.L. large label

1080 S.A.R.L. large label

1097 S.A.R.L. large label

1137 S.A.R.L. small label

1147 S.A.R.L. small label

1219 S.A.R.L. small label

1244 S.A.R.L. small label

1309 S.A.R.L. small label

1352 S.A.R.L. small label

1359 S.A.R.L. small label

1443 S.A.R.L. small label

1460 S.A.R.L. small label

1506 S.A.R.L. small label

1518 S.A.R.L. small label

1594 S.A.R.L. small label

1665 S.A.R.L. small label

1804 S.A.R.L. small label

1834 S.A.R.L. small label

1871 S.A.R.L. small label

1960 S.A. small label

2042 S.A. small label

2075 S.A. small label ( Albert Falco's CG45 )

2112 S.A. small label

2123 S.A. small label

2139 S.A. small label

2142 S.A. small label

2143 S.A. small label

2199 S.A. small label

2301 S.A. small label

2542M S.A. small label

2630M S.A. small label

2668M S.A. small label

2676M S.A. small label

2717M small label (no S.A. marked)

2772 M S.A. small label up side-down

2851 S.A. small label

2883 S.A. small label

2886 S.A. small label

2940 S.A. small label

2992 S.A. small label

3035 S.A. small label

3077 S.A. small label

3128 S.A. small label

3214 S.A. small label

3414 S.A. small label

3572 S.A. small label

3629 S.A. small label

3707 S.A. small label

3783 S.A. small label

3920 S.A. small label

4051 S.A. small label up side-down

4067 S.A. small label up side-down

4166 S.A. small label up side-down

4228 S.A. small label up side-down

4353 S.A. small label

4484 S.A. small label

4622 S.A. small label

4722 S.A. small label

4791 S.A. small label

5002 S.A. small label

5104 S.A. small label

5127 S.A. small label

5206 S.A. small label

5389 S.A. small label

5421 S.A. small label

5614 S.A. small label

5723 S.A. small label

6047 S.A. small label

6053 S.A. small label

6104 S.A. small label

6172 S.A. small label

6194 S.A. small label

I would like to thank the people who participated directly or indirectly in the development of this page.

And more particularly Jacques Chabbert, Philippe Rousseau, Stéphane Eyme, Thierry Lafitte, Adair Ribeiro, Jean-Yves Tourbin and David L Dekker.

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