Finally Got My Poseidon, WOW

[guyharrisonphoto]

After saving up, I got a poseidon XStream single tank rig. I had dived servo regs for 15 years in the 80 and 90s until my gear was stolen (Tekna and Oceanic Omega). When bought new gear 7 years ago (after using rental stuff for a decade) I did not know any servo regs still existed and got an Apeks XTX. When Oceanic introduced the Omega 3, I was going to get one but could not due to its proprietary hose not being suitable for a long hose setup, but I learned about Poseidon.

I am lucky enough to live near Dive Gear Express and they set me up with a custom "streamlined" rec mode (48" hose routed under the arm with a right-angle swivel at the second stage, and a bungied necklace secondary)

I had always loved the way the servo regs breathed, how much control they gave me over how much air I wanted, and the impossibility of overbreathing them no matter how hard I was working. I thought my Apeks was (and is) a very fine breather so it was not an easy decision to drop big $$$ for the new rig, maybe more of an nostalgic indulgence I wondered?

Boy, am I glad I did! I had forgotten just what a joy these regs were, with the ultra light mouthpiece, side exhaust, and easy breathing.

Did a three tank trip. My air consumption decreased noticeably, honestly something I did not expect after all my years diving. I still had air when the DM had to surface. Hit the no deco limit on the dives instead of being gas limited. Breathing was effortless.

I know the breathing characteristics of these are not for everyone, but I feel like I came "back home" when I got this reg. I really did not think a piece of gear would make a difference in my gas consumption, but it was for real.

I'm now laid up from diving until June due to knee surgery, so I have to visit Scubaboard and dive vicariously, and make this silly post.

Still, if it is useful, or anyone has servo reg war stories, or anyone has questions about this reg, please post!

 

[ams511]

Congratulations on your new regulators and have a speedy recovery from your surgery.

 

[Eric Sedletzky]

What exactly is a "servo" reg? Is that a reference to the second or first stage. I thought there were two styles of regs, piston and diaphragm. Aren't Poseidon's all Diaphragm 1st's?
I've heard many things great about Poseidon's and I'm intrigued by them, but I know nothing about them.
I hear they are a designers and engineers wet dream.
What is the breathing quirkiness, if you can describe it accurately?
And then what did it cost and how long is the interval between services (provided it's kept immaculate inside)
Where do you send it for service and how much are the parts.
Are parts available to the DIY either black market or legit?
Sorry for all the questions, but inquiring minds want to know.

 

[ams511]

The servo mechanism is on the second stage only. The second stage can be matched with either a piston or diaphragm first stage. They are not very popular. I believe the only ones on the market are the Oceanic Omega/Hollis clone and the Poseidon's. In the past I believe the SP pilot and tekna were also servos.

 

[runsongas]

i recently got a jetstream for ****s and grins to compare to my xtx50s. downstream regs seem closer to a straw whereas the servo doesn't seem to require you to suck on it as hard after it cracks open. it almost feels like an air hose where its pushing air out once it is open. not sure it would be for everyone. could see it causing air consumption to go up if you aren't used to it.

dgx sells parts and kits for the poseidons.

 

[Pullmyfinger]

I used to have Jet streams and xstreams. I agree; I liked the way the delivered gas.......very nice!
Enjoy!

 

[guyharrisonphoto]

What exactly is a "servo" reg? Is that a reference to the second or first stage. I thought there were two styles of regs, piston and diaphragm. Aren't Poseidon's all Diaphragm 1st's?
I've heard many things great about Poseidon's and I'm intrigued by them, but I know nothing about them.
I hear they are a designers and engineers wet dream.
What is the breathing quirkiness, if you can describe it accurately?
And then what did it cost and how long is the interval between services (provided it's kept immaculate inside)
Where do you send it for service and how much are the parts.
Are parts available to the DIY either black market or legit?
Sorry for all the questions, but inquiring minds want to know.

Hi Eric

I'll try to answer your questions as best I can.

Design. I am not a regulator mechanic, so please take this summary with a grain of salt. Others on the Board, like Akimbo, will have far more expertise than I. That said, here goes (in layman’s terms) . . . The servo is the second stage mechanism. Poseidon's website has a far better mechanical explanation than I could give, but I think the main difference is that a traditional design requires you to draw against a spring that resists the intermediate pressure, until you suck hard enough to create a vacuum that moves the valve against the spring. The servo uses a valve that tips slightly to crack, and then the intermediate pressure from the tank assists in delivering the air. The servo valve simply tips more as you increase the airflow across it by inhaling, with the intermediate pressure then seeming to "push" the air to you. The design is very simple, has only a couple of moving parts, nothing, really, to wear out, It is very small, which results in a very small and light second stage. Side exhaust is not necessary to the design, but is an added bonus. So, yes, as far as design and engineering, they are superb. How this affects the breathing I will get to when answering that question.

Yes, the 1st is a fully sealed diaphragm. It has a special feature in that uses a ball-shaped part to seal, which will probably never wear out as compared to knife-edge seals. Built like a tank. 5 LP and 2 HP ports for all the gizmos you could want, with very nice hose routing for a single tank setup.

From my experience thus far, I would add to the "nothing but great" things to say. Built like a tank, breathe like a dream.

Breathing. As one poster below said, the difference between these and a traditional design is how it delivers air after it cracks. I had mine tuned to crack in 1/4 inch of water. Once the air flows, you do not need to "suck" in order to create a vacuum to increase airflow. Thus, it feels like the reg is "feeding" air to you, as opposed to you "sucking" air from the tank.

It is not like a freeflow, though, as airflow stops instantly when you stop drawing your breath. It is like assisted natural breathing. If you "suck" hard like on a conventional reg, it will inflate your lungs fast, like a storm, but never overinflate because the air stops flowing when your inhale stops. It can be startling at first, though, how much and how fast these things deliver air. Thus, the breathing takes some getting used to. Once you do, it is very easy to "sip" air, or to breathe at a shallow, slow pace, or deeply. When you really have to work hard and breathe hard, you will never be able to overbreathe the reg, it will give you all the air you can ever need.

But, it requires a diver who is more advanced and aware, and willing to make a little investment in learning to master the reg. Once you do, your air consumption can improve noticeably. The ease of airflow does NOT increase your air consumption, quite the contrary—you have total effortless control over how, and how much, you breathe.

For me, I was instinctively used to these regs having used them for almost 20 years, so using the Poseidon took all of five minutes to re-master.

As for breathing quirkiness, the Poseidon has none. It is easy in all positions, and completely dry. Effortless from 120’ (my deepest dive with it so far) to the 10’ safety stop, or diving in 6 to 15 feet of water at Blue Heron Bridge. &#8221. In the 70s and 80s, I dove my servo regs to 240’, and they were completely effortless. I dove with Rick Smith when he had Pisces divers and we were some of the first to dive the deeper artificial reefs off Miami. In those days the servo design (Tekna) was the preferred choice for many deep divers here in S. Florida.

The early designs had some quirks that kept them from widely catching on. They were so sensitive at shallow depths (less than 30&#8217 that they sometimes “stuttered” when breathing, which was irritating. You could eliminate this by learning to slow, shallow breathe and not sucking at all, but, again, it took practice to master. They also were, often, “wet” breathers as water would come in around the exhaust valve (not all of them, mainly the Omegas). They were mostly considered a deep diving specialty reg.


The Poseidon has none of this old quirkiness. It is by far the best servo reg (and the best reg) I have breathed ever in my diving.

Cost: Not cheap. My set-up, with the 1^st stage, 2 XSream seconds, 1 48” hose with right angle swivel, 1 22’ Hose, 1 LP inflator hose, 1 SPG on a 26” hose, a DIN to Yoke adapter, the bungie necklace, and a 6” HP hose for my AI transmitter (all of the hoses flexible braided you can get rubber if you want but I like braided), set me back about $900. Comparable to any top line system from Apeks or Scubapro. Dive Gear Express has, by far, the best pricing on these regs. Far better than leisurepro, even, and DGX’s service is second to none in setting up your rig exactly like you want it.

Service: Back in “the day” annual service was not so big a thing. I went hundreds of dives and years between servicing on my Teknas and Omegas. Never had any trouble or failure of any kind. Looking at the poseidon’s construction, both first and second stages, I would say you could do the same, easily, as I think they are even more solid. The manual, though, recommends annual service. There are service techs around the country (including DGX) once you look. Poseidon is not a large brand, but is a solid brand going back a long time and you can them serviced. I believe DGX also sells the service kits if you DIY. If, however, I was going on a trip to a remote area or liveaboard, I would take a spare second stage in case disaster struck (such as an anchor falling on your second stage, can’t imaging anything else making it stop working).

Older Poseidons required special hoses with overpressure relief valves. New Poseidons have the OPV in the first stage, and now work perfectly with regular hoses of all lengths.

By the way, Eric, I read your posts often, so I hope this is useful for you!

 

[dumpsterDiver]

Don't they operate at a higher IP (pressure) so you can't just slap any old second stage on them, if it were to be damaged on a big trip? I knew people who used those regs many years ago. They seemed VERY prone to freeflows (which were especially strong) and I saw the second stage of one completely fall apart- apparently the technician assembled it wrong.

I tried one once, I did not like the way it blasted air at you and as I recall it was noisy. They always reminded me of a noisy race care rather than a dependable work truck..

 

[guyharrisonphoto]

The Cyclon model needs a high IP for the second stage (166). Some of the older ones might have, also. I can only speak to my new one. The Xtream uses a more typical 125. When I said spare second stage I meant a spare Xstream. But, at that IP, a lot of second stages would work fine.

As for freeflows, I tune and set my Apeks always for maximum sensitivity. I don't notice any more freeflows on the Poseidon when I jump off the boat, and a quick turn down stops it (like every reg). When facing a strong current the Poseidon has the purge off to the side and pointing to the rear, and there is absolutely no tendency to freeflow at all, something I cannot say about front purge regs that are tuned for sensitivity. But, you are right on one thing, when they freeflow, you notice!

As for the air blasting sensation, you are not alone in that it is not your cup of tea. But, that ceases to become a problem once you get used to not consciously "breathing" on the reg by sucking in. It takes time, for new user maybe not just a few dives but a dozen, unless they can speak to someone who has gotten the different breathing technique down and so don't go through the learning curve. I was mentored by experts on servo regs so I had a nice start.

As far as noise, I am not sure I noticed any difference. On my dives, I used my Apeks as my secondary (they both worked fine off the Poseidon 1st) and kept switching back and forth to compare. The Apeks, by the way, held is own very well. In "the day" the servo just blew the others away. Now, not so much. But the Poseidon, for me had the edge maybe because I knew how to get the most out of the breathing characteristics.

As for reliability, they have a bulletproof reputation, but time will tell. "Dependable truck" is very important to me, and my previous servo regs met that standard well. Of my 1000 plus dives, probably more than half were on servo regs with never a problem, nor with any of my buddies' regs (we all used them).

Also, to clarify my prior post, the service recommendation is every two years or 100 dives whichever is first.