Regulators In History
by Nick Icorn

The original Model D Aqua-lung regulator which was later to become known as the DA, consisted of a lower box containing a large horseshoe lever and diaphragm, and an upper box for protection, opened to water pressure and containing the exhaust valve. Side clips held the two halves together, with the diaphragm sandwiched in-between. The hose assembly, which on early models used gum rubber hoses, was open at the mouthpiece and could easily be flooded. Later in 1954 non-return valves were added for easier clearing and use.

The original 1953 unit had one price only; $80.00, no discounts, no special sales. When combined with a K-valve tank the price was $142.50, With the addition of a spring loaded, constant reserve valve, tank and regulator sold for $160.00.

In 1953 models, a blue hose was adopted with a blue nameplate. These were the first U.S. assembled regulators and were U.S. Navy authorized field units. The nameplate depicted "Aqua-Lung" Cousteau Gagnan Process, U.S. Patent No. 2,485,039, U.S. Divers Co., 1045 Broxton Ava, Los Angeles 24, Cal., Use Compressed Air Only. This was the Rene Sporting Good's address in Westwood, CA.

In late 1953, Rene Bussoz sold his holdings in Rene Sporting Goods to Air Liquide France and the company was renamed U.S. Divers and eventually relocated to Pico Blvd. in Los Angeles.

In late 1954, a full face mask from France called the Natascope was offered with the regulator. Designations were changed to read DB for the regulator with mask and DA for the regulator only. In 1955, catalog descriptions listed the regulator as the DA model. Later single stage models would carry the prefix DX, DY, and DW Mistral.

In 1958, an upgrading of the regulator produced the DA Aquamaster, model #1010. Major changes consisted of the elimination of springs on the horseshoe lever and the addition of a low pressure port for "hooka" or hose attachment for surface supply. The nameplate described the unit as the "Aqua-lung, DA Aquamaster” 2 stage regulator " A small crown label was affixed over the nameplate.

In 1961, the hoses were modified to provide a softer rubber and a curved mouthpiece assembly for diver comfort.

In 1964, U.S. Divers introduced the "Royal Master" designated as model #1046. The major change from the DA Aquamaster was the addition of an 0-ring sealed cap over the stem of the hi pressure seat. This allowed H, P. air to circulate around the stem and basically balanced out the first stage from changing tank pressures. The nameplate designation was Royal Master on a red background over a gold crown lettered U.S. Divers. The small gold crown sticker was placed above the nameplate. In addition, the Aquamaster and Royal Master were fitted with a rubber handwheel in place of the wing type screw used previously to connect the regulator. In 1966, the name was revised to read Royal Aquamaster.

In 1970, the nameplate was changed from a rectangular brass plate to a larger round foil label with adhesive backing.

In 1973,the DA Aquamaster regulator was dropped from the line leaving only the Royal Aquamaster. In 1975, this too was dropped and the two hose regulator passed into extinction. Of course a number of units were still available until the stock was depleted.

When Cousteau originally designed the regulator it was to be worn with the shorter European tanks, allowing the regulator to be positioned between the shoulder blades almost on a direct line with the lungs. In the U.S. with longer cylinders, the regulator was forced into a higher position increasing the pressure differential on the lungs. This coupled with the variety of training techniques taught to clear a two hose regulator added to its final retirement.

What is interesting to note is the clearing techniques were not really required. Simply leaning to the left, gravity and the weight of the water cleared the mouthpiece without any exhalation required.

In comparison to some modem day regulators, the two hose regulator provided a larger, more sensitive four inch diaphragm, a smoother flow of air thru the hose system, a more comfortable mouthpiece due to the buoyancy of the hoses, and quieter operation with exhaust bubbles exiting behind the diver.

Many photographers, professionals, and scientists still relish and use these relics of the past.

After the advent of the two stage, two hose regulator the first of the single stage, two hose regulators began to appear. The single stage pressure reduction dates all the way back to the Rouquayrol-DenayrouzeAreophore apparatus of the 1860's. In 1954, U.S. Divers introduced the DX Overpressure Single Stage Regulator. The unit used a fulcrum lever principle consisting of a pin type valve centered in a body with two levers interacting across the valve and in contact with the diaphragm. On inhalation the diaphragm depressed the two levers, which in turn depressed the pin type valve, allowing air to flow directly from the cylinder. To further enhance the air flow and to give the feeling of over pressure, an internal hose was connected from the valve body to the mouthpiece "a hose within a hose”. For a small nominal fee, most dive stores would remove the internal hose and eliminate the "gushing" of air. The top cover was chrome plated and polished and the nameplate was yellow. The mouthpiece consisted of a metal tee. The unit retailed for $60.00, while the two stage regulator was $80.00 in comparison.

In 1955, a slightly modified regulator was introduced under the name of DW Stream Air. The over pressure hose was eliminated and a different orifice was added that angled slightly off center to provide turbulence and overcome the strong venturi action of the DX regulator. This regulator was also manufactured with a phenolic resin case and later in cycolac plastic in both black and brown. The same metal parts were used as with the DW Stream Air regulator.

In 1956 both the DW Stream Air and the DY plastic cased regulator were combined into one new regulator, the DW Mistral. Again, a re-designed orifice provided a more even breathing flow. The orifice included side vents to provide turbulence within the case to prevent too strong of a venturi action on the diaphragm. In 1958 the part number 1008 was assigned to the Mistral regulator. Later the DY JetAir plastic regulator was reintroduced.

In 1965, the Royal Mistral, part number 1054, was added to the line. This utilized a poppet and sleeve assembly with an 0-ring sealed cap to provide a balanced part system unaffected by the changing cylinder pressures. The orifice used on previous models was eliminated. The following year the Royal Mistral was discontinued giving way to the existing two hose regulators and the influx of single hose systems.

In 1954 the first American-designed and produced regulator, the Divair, was offered. Manufactured by the L.G. Alpin Company of West Caldwell. New Jersey, and marketed by the Healthways Corporation, it featured a double lever system and a cast bronze back plate. Added to the back of the regulator was a twist-on reserve air knob. Unfortunately it was very difficult to reach.

The Divair was plagued by electrolysis from dissimilar metals used in its construction. In 1955 in an effort to eliminate the problem the back plate was changed to aluminum. This too created more chaos, and finally in 1956 a plastic back plate was added as well as changes in other materials. In addition a lever was added to the reserve mechanism in the 55 and 56 models. A unique feature was that the reserve mechanism could be adjusted for the different pressures.

To compliment the regulator, Healthways added the Hope-Page mouthpiece designed by Rory Page. A well made non-return valve system, it could be adjusted for maximum comfort. 1956 was the final year of the Divair regulator and Healthways went on to newer designs.

The first regulator to be designed and made under government contract was the Northill Air Lung by the Garrett AiResearch Corporation in Torrance, California in 1954. Designed by Robert Kimes and Robert Kesler, it was released for sale to the public in 1955.

Consisting of a bronze cast housing, it had several unique features: A built-in reserve lever with a pull type lanyard that could be attached to the front of the harness, a rotating shut-off mouthpiece to prevent water from entering the hoses, non-return valves, and an exhaust system incorporated into the outer edges of the diaphragm, closing on inhalation and opening on exhalation. While still being a balanced single stage regulator, it had three levers balancing the diaphragm; a well-made and very distinct regulator, Garrett also supplied the first aluminum cylinders with the Northill regulator.

In 1955, a new company entered the market: The Davison Corporation in Evanston, Illinois. The name was shortened to Dacor. Their initial regulator, designed by Sam Davison, Jr., was referred to as a two stage regulator, but actually incorporated a single stage lever system. What was unique was that it utilized two diaphragms. An inner diaphragm located over the lever assembly for inhalation and an outer diaphragm incorporating an exhaust valve mounted in the center of the diaphragm. This allowed exhaust air to be directed to the outer chamber separate from the inhalation chamber.

Later a unique device was added to the regulator: a knob which connected with a rotating vane mounted beside the regulator to deflect the flow of air. This was called the "Dial-a-breath," allowing the diver to make his breathing harder. The theory was that harder breathing conserved air for the diver, "You didn't use as much""

In 1957, Healthways appeared with a completely new regulator, designed by Sam Lecocq. Called the Scuba it featured the first clamp ring to hold the top and bottom cases together. An angled top case featured a series of large slots around the side for water entry. Inside, a well designed bracket held the two levers in a fulcrum position. The exhaust system utilized a diaphragm to cover the exhaust port. In addition, it had bleeder holes on the back side of the case in case of exhaust diaphragm stickage. This was coveted by a sealing band. Later a flutter valve was also added in the exhaust end of the hose. In 1960, the case was redesigned to a more modern appearance and an exhaust compartment was added inside the top case cover. A standard round exhaust valve completed the assembly. In addition in 1962 an internal yoke screw was added in place of the wing nut screw. The name was changed to read Scuba Deluxe. In 1964, this regulator gave way to the influx of single hose regulators.

In 1956 W. J. Voit Rubber Company entered the diving field. Rather than produce their own, they entered into an agreement with U. S. Divers Corp. The first regulator produced under their name was the VR-1 Sportsman which internally was the same as the U.S. Divers DW StreamAir. The outside case had a distinctive pattern on the front with a round Voit label in the center. The case halves were connected by a clamp ring. The hoses were either gray or tinted light green and molded by Voit. Vanilla flavoring was added to reduce the rubber odor. This model was improved in 1960 with the orifice being changed to the same as the USD Mistral regulator and the number and name was changed to V-22 Polaris 50. A complimentary version made from blue ABS Cycolac plastic was introduced as the V-55 Blue 50 Fathom using the same internal parts. This regulator was the same as the USD DY JetAir regulator. Their second regulator was not a single stage, but a copy of the USD Aqua-Lung two stage regulator with the name and part number VR-2 Mariner. This too was changed in 1962 to the V-66 Navy regulator (USD Aquamaster).

In addition, Voit had a mechanism of their own design in their third regulator, the VCR-2 50 Fathom regulator. The upper case cover was a distinctive anodized blue in color. The mechanism design was a forerunner to the downstream second stages of the modem single hose regulators. This regulator was also made with a blue ABS cycolac plastic case and designated the V-5 Blue 50 Fathom. Both models were discontinued in 1962.

In 1958 with the release of the "Sea Hunt" TV series starring Lloyd Bridges as "Mike Nelson," Voit had a heavy increase in models and sales. In addition, they sponsored a Sunday TV program called "Territory Underwater," featuring the Brauer Brothers of Ski N' Dive in California,

In 1961, the Sportways Company, formed in 1958, introduced the Dual-Air, a two hose regulator to compliment their popular Waterlung single hose regulators. While a two stage regulator, it was unique in that it used a single hose first stage mounted outside the box with a tilt valve second stage inside. The exhaust system was identical to the Healthways Scuba Deluxe regulator. Both regulators were designed by Sam Lecocq. Later the tilt valve was replaced with a downstream lever and renamed the Hydro-Twin.

These were the magical days of diving, with Jacques Cousteau and Mike Nelson showing us the way. Two hose regulators, both two stage and single stage were in the forefront. Divers on the beach drew a crowd when entering the water. Training programs revolved around "How to clear a two hose regulator". The underwater world was a challenge, and all this took place during the early 50's and 60's. It was a magical time.

U.S, Divers and Voit images courtesy of Nick Icorn. French image courtesy Leslie Leaney,

The author* Nick Icorn is an internationally renowned authority on scuba diving and is the principal of Nick Icom's Museum of Diving History. He is now in semi-retirement after a lengthy and distinguished career in diving. An accounting of his career appears in HD 6 p 28. He recently received the Conrad Limbaugh Award to add to his two NOGI's and various other awards. Nick is Director of Sports Diving for the HDSUSA.


HISTORICAL DIVER No. 16 Summer 1998.