Vintage Double Hose

Here's a bit of an odd-ball. I think I posted this photo of a reg I saw for sale once. Aqualung Sea Frontier.



Look at that adjustment knob on the 2nd stage!

I did not know that about the Aquarius Luis. I have two of them and I never dove them. One I have had for a number of years and I just used it to run air tools off of a scuba tank.

Doc Ed that second stage looks just like the one USD made for Kirby Morgan for their superlite helmets. I wonder if it is a commercial USD product?

Any idea of the vintage/model of these (yes, one is a Calypso):






Got these and some Dacor Olympics from a shirt-tail relative some time back...

The first one is a Deepstar (non-balanced piston first stage).

It was around in the early 70’s, but I think it was introduced in the late 60’s. It was a very common low end regulator. Several of my high school buddies used to dive it.

The Deepstar was replaced by the Aquarius, but I think there was some overlap of when they were available.

The best way to confirm the approximate availability dates is to download the US Divers catalogs from the down load section. I say approximate, because many items were available before and sometimes long after they were shown in the catalogs.

The Deepstar in particular is one regulator that I think that was available (probably from the distributors, but maybe even from USD) for a long time after it might have disappeared from the catalogs and was replaced by the Aquarius. I just remember having them both available for sale about the same time period.

The Calypso second stage is an older style second stage, I think mid to early 60’s. This can be easily confirmed from the catalogs. I would look it up, but I downloaded them at home, not here.

Neither one is a Conshelf, but they did share the same second stage.

Thanks. Tough to match it up. By the configuration of the base of the first stage it might be '70, but the knob is wrong, and is never shown that way (perhaps the missing '71?) or has been swapped out. The smooth face plate seems to have shown up in '70, and shows no residue from a sticker... The Calypso is a mystery too.

At least I now know it is a DeepStar.

Were all the seconds basically the same, and used on the various firsts?

The only second stages on USD single hoses that were unique (off the top of my head, so don't sharpshoot me)were:

-Aquamatic and deluxe Aquamatic
-Original Calypso second stage
-Aquadiv and Aquadiv Deluxe

Pretty much everything else shares a common second stage. Regs made during the same period have the same second stage. The 1965 Conshelf VI, for example, has the same second stage as the Hydrolung Supreme as they were made during the same period. Around 1970 USD went to the "magnum" second stage, which featured a larger diameter exhaust valve. Those 1970's metal second stages lasted until USD went to the janky 80's plastic ones during the "Crockett and Tubbs Era."

A couple of other tid bits of info:
The difference between the Conshelf 20 & 21 was that they used a different 2nd stage. The Conshelf 20 was their first modern plastic 2nd stage, and the geometry of the case was redesigned with the Conshelf 21 going forward.
In addition to the Royal, they had the Royal SL that had a diver adjustable exhaust valve on the side of the case. The original Royal had a tendency to leak sometimes in certain positions from the side exhaust valve. They went away with it completely along with the balanced 2nd stage with the introduction of the Pro Diver.
The SE2, SEA, & Pro Diver was more than just the physical characteristics of the first stage. They had different 1st stage flow rates, with the Pro Diver being the highest, followed by the SEA, then the SE2.
The difference between the SE & SE2 had to do with the exhaust valve support. The SE had I believe 5 or 6 legs that held the exhaust valve. Those extra legs increased the exhalation resistance of the reg. For the SE2, the exhaust valve support was modified to 3 legs and the extra legs that were removed still retained a small leg around the perimeter of the exhaust valve to help prevent the exhaust valve from being sucked in.
There was also a modified version of the Conshelf 12 that sold that had a right angle swivel where it attached to the 2nd stage with a longer hose that ran under the armpit instead of over your shoulder that made it an extremely comfortable reg to dive with, but it was short lived.

The other unique 2nd stage they had was the Professional Aquamatic for one year in 1960. Looks like a Calypso 2nd stage, but the internals were completely different.

Awesome information Mike! This thread is definitely worth keeping

Ron, there was another odd second stage used in the Royal Aqualung models. It is a balanced design with a bunch of parts. To my knowledge it is the only one in the USD line that was balanced unitl recent years. I have one on the bench in pieces deep in my round-2-it pile......hummmm might be the perfect octo for my Krakan.

I have PDFs of both stages if anyone would like copies.

Ron, Thanks for starting this thread. I find it fascinating that so many models are basically very similar. It shows that someone understood the "if it ain't broke, don't fix it" philosophy in their R & D department . Mike

You are most certainly welcome Mike

Fortunately, I ran across this thread while searching for information about a black beauty I have. The purge disc has a decal "Aqualung Conshelf XIV" However, this particular second stage does not have a service plug as pictured in the parts diagram or as in the previous post with a beautiful all chrome Conshelf 14.




Also, just to triple check. The "inlet fitting" is just that, right? The part that appears to be a jam nut is fixed, or is there a secret only those with arcane knowledge possess?



TIA

It looks like an older conshelf XIV second that someone put a new exhaust tee on. Our shop does this sometimes. The old tees are not made anymore, but the new one will fit on the old boxes without the port plug. On those models, the inlet fitting is permanently fixed (like you have it there), and has the second stage volcano orifice integrated permanently into it. I have never seen a black one, so I wonder if it was painted by someone. The inlet fitting is clearly chrome underneath.

As an aside I serviced one of these from 1978 a few weeks ago, and it had the original seat in it. It was still holding IP when I rebuilt it.