In 1918, ‘Ohgushi's Peerless Respirators" had been invented, patented, and put into production by the Tokyo Submarine Industrial Company. Was used by the Japanese Navy, on salvage work and used for coral fishing. According to the company's literature: ‘The Ohgushi's breathing apparatus (diving machine) of our company is of the invention of a Japanese. It is the newest machine patented not only in Japan, but  also  in Europe and America, and is provided with all the arrangements wanting in other kinds of machines. It is not too much to say that it holds the unique position among diving machines of the world’.

‘Ohgushi’s Peerless Respirators’ by the Tokyo Submarine Industrial Company


the scrapbook of diving history

The respirator is shown as being capable of use with one or two compressed air cylinders, or as a ‘surface demand’ valve which is supplied from the Watanabe four-cylinder reciprocating hand pump. According to the document the hand pump was capable of producing a pressure of 200 Bar. Furthermore, according to the document:

1. ‘The experiment made in October, 1918, upon the diving apparatus of Yokosuka Harbor in the presence of the Naval authorities by their request won their high favor, and by their request the machine was adopted in each and every naval station.’

2. ‘The machine was employed during the years extending from 1918 to 1919 in  the taking into parts the Norwegian vessel CALENDAR sunk outside Nagasaki  Harbor at the depth of 200 feet of water and accomplished its object to the satisfaction. Another successful employment of the machine was made in taking into parts the English vessel NILE at the depth of 200 feet off the coast of Yamaguchi prefecture in 1919.’

3. ‘In July of 1919 by the request of the Kohchi prefectural authorities, three  different experiments were made upon the diving machine in  the presence of the local prefectural authorities, members of the  Fishery Association,  journalists and others, and obtained the following results:

        No. of Expt.    Place                Depth      Time

        ------------    -----------------    ------     ----------------

             1          Off Ashizuri-zaki   282 ft.    10 mins. 10 secs.

             2          Off Kano-zaki        324 ft.     9 mins. 10 secs.

             3          Off Kano-zaki        284 ft.    15 mins. 00 secs.

Afterwards, we succeeded in collecting corals at the depth of 375 feet of water in the same prefecture.’

How did the Ohgushi respirator work? The respirator itself was remarkably similar to our present day dive masks. Oval in appearance, it covered the eyes and nose, and was made of rubber with a face glass clamped in by a metal band. It was held on the face by a simple harness made of stretchable rubber tubes held together with a hook and eye at the back of the head. Attached to the bottom of the mask, in line with the mouth, but no penetrating the mask  at this point, is an ordinary mushroom type valve, held shut by a rubber sleeve around the stem. Air, whether from a surface pump or from the cylinder(s) on the back is fed into the valve and, from above the seating, it is led by an external pipe into an air inlet at the side of the mask. Projecting from the rear of this valve are two levers, one above the other, one fixed, the other pivoted, and these are held between the teeth. To obtain air, the diver clenches his teeth and inhales through his nose. To exhale, he opens his teeth, shutting the valve, exhaling through his mouth.

Above the Watanabe four-cylinder reciprocating hand pump. According to the document this pump could achieve a pressure of 200 bar, unfortunately there is no technical drawing or explanation which shows the exact functioning of the pump but it could well be that is was inspired by the booster pumps which were manufactured by the German company Dräger in Lübeck since the early 1900’s.

Above the actual SCUBA apparatus in a single tank version. 

With special thanks to mr. Roche from France for his contribution to this chapter