Maurizio Baldinucci

I recently had the opportunity to strip-down and internally analyze a very strange double hose regulator that my friend, journalist and collector Luigi Fabbri recently took over from the daughters of the Florentine diving pioneer Giuliano Miniati (see Figure 1), a very well-known character among local divers since the end of the 1950s and passed away a couple of years ago. When Fabbri had the opportunity to look and take photos of the Giuliano Miniati's collection in 2009, he found himself faced with a sort of "cave of wonders", an absolutely incredible place for the number and rarity of the diving equipment collected by Miniati over few decades of activities within Florentine diving community (see Figure 2). Today this collection no longer exists having been progressively sold over the years to various collectors after Miniati's retirement from operational activity.

Figure 1 Figure 2

Luigi had the opportunity to take some pictures of this unit, identified on the front plate as Nettuno II (see Figure 3 and Figure 4), already a few years ago together with other unique diving gear belonging to Miniati's collection, pieces of equipment which are visible on his very cultured and vast website

Figure 3 Figure 4

The Nettuno II regulator, together with some underwater camera cases, some gauges and little else, were among the last pieces of the original collection, pieces recently put up for sale by Miniati's daughters.
Unfortunately, beyond the photos collected by Luigi, no other information was available on this regulator nor was it subsequently possible to find any information in books, catalogues, price lists and so on. The only reference I was able to find on this model is taken from a short writing signed by Giuliano Miniati, also received from his daughters, in which the Florentine pioneer describes his youth problems with ears compensation. At a certain point he says:"...My next purchases were a used Pirelli wetsuit which I paid 10,000 Lire, a ten liter single tank and a Nettuno regulator built in Turin for 20,000 Lire and so I began to go underwater at the Tino where there was a wonderful seabed...". The information on the alleged Turin company that would have built the Nettuno suggested me to look for some information from old divers of that city who I know but I did not find any confirmation in that direction.
Having lost any possibility to find useful information on the origin of this regulator, my hope was that the disassembly and observation of the internal components of the unit could allow us to find useful clues to place this device in its correct historical and commercial context. Unfortunately, as we will see in the next part of the article, the information collected during the disassembly of the unit was not sufficient to find solid evidence on the origin of this model and, in certain cases, it also generated other questions that still remain without an answer.
Let us now analyze in detail what emerged during disassembly of the device.
a) The mouthpiece is marked Spiro-Sub (see Figure 5 and Figure 6), and it is known that this brand was owned by Cressi which used it for the marketing of equipment produced by other companies, among which there was also La Spirotechnique.

Figure 5 Figure 6

Starting from 1959, the French company granted Spiro-Sub the construction under license of the famous Mistral regulator. This version was identical to the French version except for the mouthpiece, which Spiro-Sub proposed in two "custom" versions: a basic one without "acquastop" valves and one with integrated snorkel and surface-dive switching button, the special mushroom type exhaust valve and the identification plate (see Figure 7, Figure 8, Figure 9 and Figure 10).

Figure 7 Figure 8
Figure 9 Figure 10

b) The internal mechanism of the regulator (see Figure 11) is almost identical to that of the Mistral apart from the absence of the Venturi effect nozzle and the system for regulating the position of the pressure reducing device upper lever (see Figure 12).

Figure 11 Figure 12

c) The corrugated hoses, the main diaphragm and the duckbill exhaust valve are the same as those of the Mistral (see Figure 13 and Figure 14).

Figure 13 Figure 14

d) The front and rear boxes making the body of the regulator are different from both those of the Mistral and those of the Royal Mistral (see Figure 15 and Figure 16). I have analyzed dozens of other models available on the market between the end of the 1950s and the beginning of the 1960s but I have not found regulator bodies absolutely identical to those of the unit in subject. This suggests that these two components were built specifically for the Nettuno II.

Figure 15 Figure 16

e) The connecting yoke to the air tank valve and the hexagonal head yoke screw are also similar but not the same as those of the Mistral (see Figure 14).
f) The internal and external stickers visible in the photos (including that with the name Nettuno II) seem temporary and were probably obtained from prototypes printed on paper films and then protected with a layer of resin (see Figure 15, Figure 17 and Figure 18).

Figure 17 Figure 18

Looking at the stickers placed inside the front box, a couple of questions arise spontaneously: why in a "made in Italy" model, as clearly indicated on the front plate and which was probably at prototype level or at most pre- series, did the manufacturer even decide to apply a sticker in English? Perhaps this was simply taken from another application and adapted for the purpose. And again: what does the number "1061" applied to the lower internal part of the front ox indicate? If, as I suppose, it is a serial number, what correspondence can such a number have with the fact that we are probably dealing with a prototype or pre-series example? It is true that in other similar applications of that period the serial numbers were normally started not from one, as would be natural, but from much higher values ​​and therefore as, for example, the number 1000 could have been.
And finally the last and completely legitimate question: if this example is called Nettuno II, then did a previous model called Nettuno or Nettuno I also exist? To our knowledge we have not found any trace of this model. As anticipated and as can be seen, the internal analysis of this unit has raised further questions rather than providing answers.
Therefore, with the very few elements available to date I can only suppose that this unit was a prototype created by Cressi and delivered to Giuliano Miniati for testing trials before the decision to possibly put this model into production. This hypothesis is completely logical precisely because of the absolute lack of any reference to the manufacturing company, both within the identification plates and in any other area of ​​the regulator. In other words, no one, outside of a close circle of people working on the development and validation project, had to know that the company was developing its own product as an alternative to the one it was marketing under license in the same period. It is then probable that other prototype specimens were produced by Cressi in the same period for testing purposes and perhaps made available to other well-known diving pioneers and experts with whom the Genoese company had relationships of trust. Perhaps among these there was also a previous version of the same regulator identified as Nettuno or Nettuno I. Unfortunately, I have not found any trace of these possible further prototypes.
This whole theorem is based on the fact that La Spirotechnique, after a few years of collaboration with Spiro-Sub, was thinking of assigning the distribution rights of its products (including first the Mistral and then the Royal Mistral) to Technisub, the diving equipment company founded by Luigi Ferraro in 1962. This decision was based above all on the excellent relationship between Ferraro and Cousteau, the latter also president of the French company, who were both part of the board of directors of the newly formed CMAS. It was therefore probable that Cressi was thinking of its own product to market instead of the licensed Mistral. Then we know that Cressi never actually produced double hose regulators but started directly in 1963 with a single hose model initially produced by Scubapro, a model which it subsequently customized and produced on its own (see Figure 19 and Figure 20).

Figure 19 Figure 20

We close this article with the hope that among those who read it there will be someone capable to provide further details and information on this regulator and all the prototype models connected to it.