We're a talking about vintage U.S. Divers double hose scuba regulators here. Introduced in 1958 the DA-"aqua-master" was a mainstay of the dive industry for many years. It was followed by a balanced version, the Royal "aqua-master", A.K.A. the RAM. We're going to take this baby fit it out with all of the latest and greatest components and bring it into the 21st century in a way the original design engineers never imagined. But first a little background about what this thing is and why we want to mess with it.

In the 1970s double hose regulators began to fall out of favor with the advent of smaller, lighter single hose models. The DA-"aqua-master" ended a 15 year run in 1973. The demise of the double hose configuration was further compounded by the proliferation of connections that newfangled accessories required. The original double hose regulator delivered breathing air to the diver and seldom had connections for much else. Divers understood their air consumption and a J valve on the air cylinder held an air reserve to let them surface if they stayed down that long. Before long divers were looking for places to connect buoyancy compensator inflaters, alternate second stages, drysuit inflaters, pressure gauges and even air integrated computer transmitters. The final blow came with the age of the litigator. Liability wary dive boat operators would not permit divers to dive from their boats without all of the modern "safety accessories".

And so it went. For many years there were isolated divers still using the older gear on their own terms. Eventually like all things old the double hose regulator came to be regarded as collectible vintage gear. Enthusiasts could find banjo fittings that allowed the connection of a cylinder pressure gauge by sandwiching the banjo between the regulator and the valve yoke face. A few diehards whose regulators included hookah ports cobbled together the plumbing needed to add the modern accouterments but the arrangements did add failure points and appeared kludgey.

Were it not for the Internet I have to wonder if this would be the end of the story. Several vintage dive gear enthusiasts started web sites and began to dabble in parts. Most of the available parts were old stock that would turn up when an old dive shop closed up or decided to clean house. Slowly some of the perishable parts were reverse engineered and put back into small-scale production to support the growing group of vintage equipment divers. The sites also included discussion forums where diver worldwide began to form a community.

When U.S. Divers went on to produce single hose regulators the internal working of the first stage regulators were by and large taken from the aqua-master series. Parts were fine tuned over the years to include modern materials and things evolved slightly but the changes were not radical.

Somewhere along the way a double hose regulator enthusiast / engineer realized that with the production of a new machined nozzle body any DA or Royal aqua-master regulator could be upgraded to have a balanced first stage that was serviceable with contemporary, readily accessible parts. While he was at it extra ports were added to the nozzle body to tap into the high pressure supply for the connection of a pressure gauge. The concept soon evolved to include low pressure ports for the modern accessories. Partnering with Vintage Double Hose.com the Phoenix Nozzle and related components were acquired and put on the market.

The Phoenix had risen! The dowdy vintage double hose regulator had new life breathed into it, no pun intended. A good many part supply issues had evaporated. Divers do not have to do without the modern accouterments and the resistance from charter operators vaporized. With this quantum leap the vintage diving Web sites and some second tier suppliers began filling in the gaps by recreating many of the old perishable parts with refinements in design and materials. Before long vintage equipment divers would be sporting more silicone than a Victoria's Secret runway show and more chrome than your father's Oldsmobile.

Not long after I began diving in 2005 I came to know one member of this community, I have since come to know many more. Seeing the Phoenix rise I decided that I would enjoy diving such a rig. Starting in the fall of 2006 I began the process of pimping a well worn DA-"aqua-master" into a Phoenix Royal "aqua-master", my PRAM. What follows should tell the story.

Footnote: Since this page as created in 2008 a lot has happened. This 2012 update includes all of the latest and greatest.

The process starts with a tired old beater like the one shown here. They can be found for sale at dive shops, yard sales and on eBay. Note the lightweight yoke and small clips used to hold the "cans" together.
	Here is my actual outer can. This is the one most visible. The original ID tag is intact but this regulator was dove hard and put up wet. The photo does not bring it out well but there was even a good sized dent at about 10:00 right on the corner.
After heading out for a "Show Chrome" finish the result is spectacular. The process involves getting the brass parts impecably clean and smooth. Then there are dips in copper, nickle and chrome. The surfaces are buffed to a mirror finish between each dip. A satin chrome which was one of the original finishes can also be reproduced. Other owners are getting eye catching results with black or colorful powder coat finishes. In some cases the two halves get finishes to provide contrast such as bright and satin chrome.
	A new mouthpiece was needed. I found one but it was mightly grungy. After a good brushing with toothpaste and a silicone grease marinade it was looking like new. Genuine "aqualung" no doubt about it! This was the end of the damage control part of the project. The follow-up to this component was an upgrade to a silicone rubber reproduction. No need for another picture, they look the same!
Next comes a full rebuild of the actual regulator including the new Phoenix Nozzle. Once installed 3 high and 3 low pressure ports will be availabe to configure my rig. The resulting first stage will be servicable with contemporary U.S. Divers parts. This part like the cans features a bright chrome finish.
	The diaphragm is the vital link between the diver calling for air and the regulators response. The only logical choice for my rig is this state of the art reproduction diaphragm molded from a silicone rubber compound. The refined geometry and stable material means that this unit will consistently deliver the air I need and do so for a long time. These silicone diaphragms have a noticably more repsonsive behavior that the original rubber versions.
Now it's time to close the regulator and it's bye bye to those vintage clips (see inset) and hello to a one piece single screw band clamp. This clamp makes getting in and out of the regulator for inspection or maintenance a breeze and it can be removed without a lot of fussing. It provides the perfect fit to maitain alignment of the two can halves and the diaphragm assuring precise response for years of diving. Precision formed from stainless steel it will remain atractive over the years.
	Inside of the mouthpiece are 2 mushroom valves to direct the airflow. The basis of the valves are these cages or "wagon wheels". Shown on the left is the traditional square sectioned design that has rectangular spokes. To help our PRAM be all that it could be we installed the new modified version. The tappered spokes offer less resistance to every breath I take and lessen the breakaway force of the 2 mushroom valves for silky smooth air delivery and exhaust.
Speaking of mushroom valves look at what we have here! Reproduction valves molded from silicone rubber. This material will perform consistently through a wide range of conditions whether in the Carribean or under the ice. The material is also highly resistant to all of the effects of aging. The design is optimized to make for silky smooth breakaway on every breath while keeping all of my air flowing in the right direction. They also prevent the entry of water thus protecting the regulator and making clearing easier should the mouthpiece get flooded. One of these assemblies is in each side of the mouthpiece. They are both positioned in the same direction forming a pair of codirectional check valves. The valve on my right will open when I inhale allowing me to breathe while the other will close preventing the loss of the fresh air and holding back any stray water that may be in the exhale hose. When I exhale the valve on my left will open letting my stale air pass to the duckbill while the other will close to isolate the air delivery valve.
Concealed inside the exhaust side of the regulator is this strange creature. It's called a duckbill and it is what lets my exhaled air escape in a location very close to the dipahragm that controls the air I will inhale. This close proximity makes for a naturally balanced breating effort. The indicated edges are actually slits in the normally collapsed bill that will open when expanded by exhaled air. The result is a fluttering motion as the diver slowly exhales a breath of air. The fact that the duckbill spends most of it's life in the closed position and is subjected to the dive enviornment takes a toll on this item. Once again it's bye bye to conventional rubber and hello silicone. This silicone duckbill valve will patienly wait for use and remain stable for years of diving. Normal flushing or rinsing should be the only required mainenance.	As much as the silicone duckbill was a big improvement there were certain design drawbacks that it just could not overcome. Positioning could be unpredictable, the large surface area could still offer resistance and it could even do a turtle neck up into the hose. The soulution came with the duckbill eliminator. This clever add-on precisely locates a modern mushroom valve precisely were it needs to be for perfect function first time and every time.
Molded with a silicone rubber compound these hoses should last a lifetime. The color was developed to be faithful to the original factory hoses. If you look closely you will see that the hoses even include the mold parting line ridges running the length of the hoses just like the originals. The silicone rubber and perfectly proportioned convolutions make for a very compliant hose that allows good freedom of movement. Even when diving in cold weather they remain soft and comfortable.
	The original label has been set aside for cosmetic and accuracy reasons. In it's place is a custom metal label from Faux Label Works that includes the unique serial number of my Phoenix nozzle. A pressure sensitive adhesive backer holds it in place. The mark of the Phoenix also graces the yoke screw knob.
Now that we can have the modern accouterments on our double hose regulator we needed an appropriate alternate second stage. We were able to locate a brand new 1980s's vintage U.S. Divers Conshelf "safe second". It's somewhat newer than the base regulator but it has a reasonably vintage look to it. It's a very nice breather.
	No more whimpy yoke for this rig. Air cylinder pressures have increased considerably since the heyday of the DA-"aqua-master" and a generous fill on a modern high pressure cylinder could result in disconcerting yoke distortion. That concern is a thing of the past with this current production full weight bright chrome plated yoke. It's mated with the companion yoke screw that includes a large knob for a good grip. Topped of with "the mark of the Phoenix, da knob don't lie.
The original second stage delivery valve had its share of issues. Friction between the diaphragm tabs and horseshoe was considerable. The adjustment was time consuming and difficult to lock. Even a routine cleaning meant getting the diaphragm tabs realigned for correct operation. 2012 brought the HPR second stage. It's a drop-in replacement that is insanely easy to adjust and it no longer relies on those diaphragm tabs making it a breeze to open it up for routine inspection. The new horseshoe has non-metallic glides that freely move on the diaphragm disc. Even the venturi assist is adjustable!
Here is the finished unit, mounted and ready to go. Shown here on a simple pack & harness I also dive my PRAM with my contemporary BC. The regulator handles my HP cylinders with ease.
	It's shiny, what more can I say?
Shown from the back you can see where all the action is. As pictured BC and drysuit QD hoses are connected along with an alternate second stage and an instrument console. The console is connected using an Oceanic Data-Link connector (lower left) making it easy to move between regulators.

So there you have it. The resulting regulator behaves unlike any of todays regulators. With the regulator out behind you there are no more bubbles in your field of view, running up your cheek or getting rapped in your hood. The air in the breathing tubes provides a degree of separation between you and the regulator for a more natural feel to breathing underwater. The sump of the mouthpiece can accompdate a little wetness that humidifies each breath making dry mouth a thing of the past. It breathes nicely and since the exhaust path is separate from the air delivery the workings of the regulator stay clean and dry for long life and reliability. This results in the ultimate in eviornmental sealing. While this is not a purely vintage rig I like to think it melds the best of the past & present. The term eclectic has been rightfully used to describe it and our related blend of gear.

All of this in a package that turns heads and begs questions from people everytime you mount it to a cylinder. While for the sake of telling the story much of it reads "I did" I have to acknowledge that without the kind support and mentoring of members of the vintage diving community this project would have never taken place. My regulator is by no means unique, many other divers are running very similar configurations. It is also possible to purchase a completely overhauled and updated regulator of this sort from Vintage Double Hose.com.com.