Favorite Doube Hose Regulator

[ew1usnr]

Hello, Aquamaster. Thanks for the Mistral photo. The mechanisms are different, but its interesting that the actual lever piece tself looks identical between the two regulators. US Divers held the patent on the Mistral design. Voit didn't want to continue to pay for manufacturing rights, so they tried to come up with a regulator design of their own that would do the same thing, but be different enough not to infringe on US Diver's patent. Thus the 50 Fathom. Having tried both, I do think that the Mistral is better. That's probably why Voit went back to the Mistral design with their introduction of the Polaris (I love that name).

The Voit Mariner (1955-1959) was a two-stage regulator that was the same as a US Divers DA Navy. The later Voit Navy was the same as the later US Divers DA AquaMaster.

The two-stage DA AquaMaster was the same as a DA Navy, except that the AquaMaster had a venturi that improved its performance.

 

[ew1usnr]

The Dacor double hose regulators really look nice and have a number of good features. They have two diaphrams. Either diaphram can fail and the regulator will still function. The regulator case is held together with screws, making it easy to take apart. The Dacor regulators were built extremely rugged. They were not made so much like a Swiss watch as they were a Sherman tank. The model R-4 was current around 1965 and was Dacors final and most advanced model double hose regulator.
Here is what a Dacor advertisement said:
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New Model R-4 Regulator, $89.50. The world's first and only double diaphragm two stage regulator. Now a new second stage design, similar in principal to the one used in our Dacor Dart single hose regulator, offers a perfection in breathing never before achieved.
Exclusive features: Double diaphragm for double safety and greater performance (either diaphragm could become damaged and the regulator would continue to operate safely).
Used by divers at the North and South Poles. Proven efficiency to in tests to 83 degrees below zero.
Service free operation - Requires less service than any other regulator ever produced. Proven by rental shops and repair stations the world over.
Many owners report that they get 20% more diving time on a tank of air with their Dacor regulator. It is the most expensive regulator to manufacture and will prove to be the most economical to own. No compromise in quality or features for price.

 

[ew1usnr]

Here is a shot showing the R-4 double diaphragms. The diaphragm on the left is the outer diaphragm. The circle in the center is the exhaust valve. The diaphragms are held apart by the spacer ring. Exhaled air is directed in between the diaphragms. The pressure (which slightly exceeds ambient water pressure) from the exhaled air "pre-sets" the inner diaphragm (the one on the right) for the next inhalation cycle. Water does not directly come in contact with the inner diaphragm and it covers and protects the inside of the regulator case from both wet breathing and corrosion . With the screws around the circumference holding the inner diaphragm tightly in place, it is difficult for water to find its way to the inside of this regulator.

Dacor was not exaggerting when they said "Service free operation - Requires less service than any other regulator ever produced."

I disassembled this regulator and cleaned it up, but it works fine without my having had to replace ANY parts. This R-4 is close to 40 years old, completely original, and it still looks and functions as good as new. Dacor built a darned good regulator.

 

[ew1usnr]

My Trieste is my most sophisticated double hose regulator. It is a balanced diapragm two-stage regulator with HP and LP ports for attaching an inflator hose, octopus, and pressure gauge.

Also pictured is the single hose adaptation of this regulator, the Titan II. The Titan was covered in this thread:
http://www.scubaboard.com/showthread.php?s=&threadid=16815

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Here is what the ad for the Trieste said:

Swimaster cares for you way down deep. To prove it, we've come up with some exciting new diving gear for 1966. Take a look at the latest in the Voit Swimaster line, the finest professional line on the market today. Then take the plunge.

Swimaster Trieste Regulator, with a unique new design, is the smallest, most compact two-hose unit made. A remarkable fully balanced first stage is backed up by Swimaster's exclusive, easily adjustable second stage demand lever. Heavy body with non-swivel yoke prevents breaking of high pressure seals and valuable air loss. The non-return mouthpiece has a comfortable bite. Hoses feature maximum stretch for freedom of head movement.

 

[ScoobieDooo]

My favorite reg is my '63 Healthways 'Scuba' model single stage double hoser. Its easy to tune, adjust and just looks 'damn cool.'

 

[pescador775]

The only two regs considered seriously by my old group of diehards were the R. Aquamaster and the Nemrod Snark III. Both were easy breathing compared to the Mistral and other single stage. The R. Aquamaster and the Nemrod had the advantage that they would deliver copious air from high pressure (3000 psi) tanks. The Mistral and other unbalanced regs like the Aquamaster would fold and become hard breathing. Although the Nemrod was not balanced it had a trick compound lever system, venturi and high IP which made breathing easy. The Nemrod had the added advantages of strong hoses which would last for a decade and a high press outlet for SPG. Also, the Nemrod could be modified to accept one or two low pressure ports. The R Aquamaster can be fitted with LP hose and SPG (with adapter). It could be adjusted readily to a fine state of tune. Like all two hoses, they were impervious to mud and silt making them safer for wreck diving where excavation is involved.

 

[ew1usnr]

pescador775 once bubbled...
The R. Aquamaster and the Nemrod had the advantage that they would deliver copious air from high pressure (3000 psi) tanks. The Mistral and other unbalanced regs like the Aquamaster would fold and become hard breathing.

Pescador775 is correct. The Royal AquaMaster (introduced in 1964) was a balanced regulator and could handle higher tank pressures. The single stage Mistral and two-stage unbalanced diaphragm DA AquaMaster, for different reasons, perform badly at pressures much above the 2200 psi tank pressure that they were designed for. The older regulators perform at their peak when placed on a low pressure steel 72 tank.

The US Divers DA AquaMaster (see photo) was arguably the finest regulator available when it was introduced in 1958. It was sold until 1972 and was the most popular double hose regulater ever produced. The AquaMaster "incorporates the security of a two-stage unit, the versatility of a hookah, and the ease of breathing of the Mistral single stage venturi regulator. The venturi of the second stage reduces breathing effort, suction pressure, even below the easy breathing single stage Mistral regulator" (Basic Scuba, 1960, Fred Roberts).
An advertisement reads: "Engineered to provide greater air flow with less suction than any other regulator, the AquaMaster almost breathes for you. Two-stage demand valve for natural breathing. Specially designed exhaust valves for effortless exhalation. Large diaphragm for easy, normal breathing at any pressure. Tough Klear E-Z hoses have minimum air flow resistance. The AquaMaster's high standard of performance is so reliable that it has been given the official approval of many military organizations throughout the world, and has been the leader among two-hose regulators for many years.

The attached photo shows a 1960 DA AquaMaster on the left with a straight mouthpiece and satin finish case. A 1965 DA AquaMaster is on the right with a curved mouthpiece and bright finish case. They each have an octo/inflator attached to the hookah port via an adapter. For more on the adapters and octopus see: http://www.scubaboard.com/showthread.php?s=&threadid=38580

 

[ScoobieDooo]

I have regulator envy...

 

[ew1usnr]

ScoobieDooo once bubbled...
I have regulator envy...

Envy is a natural reaction to the sight of an AquaMaster.

 

[LouClrWtr]

I bought a U.S. Divers Mistral in 1958 with black hoses that I wish I still had. It was stolen about 3 years ago and still worked great.