Love my Poseidon, but I think it's time to let it go. What's next?

[diversteve]

two comments -

I don't dive Nitrox so no Ti worries.

Like the OP I just drive them - leaving service to the shop.

Arguably the best tech in the area at a shop about 30mi away - which used to sell/service Poseidon - no longer does. It's where the Jetstream was bought.

3 local shops within 10 min. sell/service Atomic. 3-4 others within 1/2 hr. including the former Poseidon dealer.

Two shops and one private dealer not near me sell/service Poseidon.

 

[Archaeological diver]

Thank you all for your great input! I think I might just buy some new Poseidons and dive them for the next 25 years .

 

[diversteve]

Allows you to re-use your existing octo - or put a yellow hose on your primary.

Poseidon uses a different IP pressure than most other brands IIRC so yours should work fine with the new one.

 

[rsingler]

Only the Cyklons are high IP.
The Jetstream is like most everyone else. 125-135 psi. You can mix and match with the Jetstream. Just not with the Cyklon.

But the 2900 and 3900 first stages are essentially the same with both models. Just tuned to different IP's. Even the XStream can be used with a Cyklon. It'll handle 160 psi easily. Poseidon just didn't bother with the certification expense of testing the XStream with a Cyklon second in the EU, from what I'm told.

 

[scubafanatic]

Just make sure you don't use that titanium reg with O2 or any rich nitrox mixes!



Parts are now easier to get than most of the big names like SP and AL.

I really don't understand why people have trouble with the 2nd stages. Jetstreams are much simpler to tear down and assemble than traditional downstream, balanced 2nd stages. I get that they are different. ..maybe that's why people avoid them. I started out diving with a Jet/Odin combination, so I find them very straight foreward and easy to understand.

I also find a few popular myths being perpetuated by those either unfamiliar with the brand, or just biased against them.
I.e.
Myth A: "All Poseidon regs use an abnormally high IP, and can't be mixed with other 2nd stages"
Reality: 0nly the Cyklon 2nd stages require higher IP (~165) and yes, that's higher than most 2nd stages are happy with. Proper IP for Jet/Xstreams is around 135, which is right where most other traditional 2nd stages belong.

Myth B: "poseidons are the only regs that will fail off, and lock out gas supply"

Reality: Jet/Xstream 2nd stages are both servo assisted upstream designs could be closed by pressure from runaway IP. That's why all early poseidon jetstreams had the OPV built into the LP hose. And after ~1991, they had an OPV built into the 1st stage housing. Mixing up an early 1st stage with a non Poseidon hose+adapter, and eliminating the OPV protection is where the risk exists. *Don't be stupid, and go swapping around reg parts if you don't know what you are doing.

Also, the only "no gas failure" I have ever witnessed was NOT with a Poseidon reg. It was a traditional design reg my wife was using, that one time we decided to use rental gear on a trip. Once we surfaced and reported the incident, the shop claimed "that's impossible, ..you must have done something wrong..etc". Shop owner hooked it up to a tank and the found out... "awe sh1t.... I guess it is possible".

No worries, I'm just an experienced recreational diver using EAN 32 typically, highest recreational mix I've ever used is EAN 36 as a few dive ops offer it for some profiles.

 

[Magnus Lundstedt]

I realy like the Poseidon Jetstream second stages, they are easy to maintain, they realy do not need much. If you adjust them right they are realy nice breathers, smooth as velvet, and they look cool.

I have mostly used them with old Aqualung/US divers conshelf SAE or Titan LX supreme (for cold water) first stge, and it is a great combination.

If you have problems with servicing your old Poseidon first stages I would consider buying new Xstream first stage or some other first stage, like Apeks, deep6 or whatever you like, or some old Conshelfs. You don't realy need any fancy advanced first stages to get them jetstreams to breathe very well. Or if you like to spend $$ buy a complete Xstream regset.

I have a bunch of different Poseidon first stages and i am going to service a couple of them for use, but i do not realy like the type of cold water cap they use.

 

[Caveeagle]

I realy like the Poseidon Jetstream second stages, they are easy to maintain, they realy do not need much. If you adjust them right they are realy nice breathers, smooth as velvet, and they look cool.

I have mostly used them with old Aqualung/US divers conshelf SAE or Titan LX supreme (for cold water) first stge, and it is a great combination.

If you have problems with servicing your old Poseidon first stages I would consider buying new Xstream first stage or some other first stage, like Apeks, deep6 or whatever you like, or some old Conshelfs. You don't realy need any fancy advanced first stages to get them jetstreams to breathe very well. Or if you like to spend $$ buy a complete Xstream regset.

I have a bunch of different Poseidon first stages and i am going to service a couple of them for use, but i do not realy like the type of cold water cap they use.

If adapting to a Non Poseidon 1st stage, Just make 100% sure you have some type of OPV (0ver pressure relief valve) on any combination using a Jetstream or Xstream 2nd stage. So that means either using the early Poseidon specific hose with an integral OPV, or one of the Omni-swivel adapters that has an integral OPV, or has a screw in OPV in one of your 1st stage LP ports.

 

[ams511]

@Caveeagle Thanks for sharing your knowledge. I always wanted to add a Poseidon to my collection. I am thinking if I want to add a second stage I can just use a regular downstream second stage as the OPV.

 

[Caveeagle]

@Caveeagle Thanks for sharing your knowledge. I always wanted to add a Poseidon to my collection. I am thinking if I want to add a second stage I can just use a regular downstream second stage as the OPV.

That would also work, but I would use one with an adjustable resistance so you can dial it In to crack If IP starts to climb. I like to have an obvious signal when a first stage HP seat is allowing IP to climb. Just my experience, but you might be more likely to spot a problem at the surface with regs pressurized before you start breathing them. Once breathing starts, you are venting the IP every few seconds, and you might not notice anything with a slow creep in IP.

I think the beginning comments of this thread might lead some to not appreciate the potential of the 3970 first stages. These are extremely high performing regulators and are still among the most reliable out there. The issue stated with the piston/cone is easily corrected. Keep in mind these are now often 25yrs old. Many newer designs perform well, but you would be hard pressed to find anything significantly better.

Sure, the Xstreams are sweet. if cost were no object, you would find several more of them on my gear rack. But without too much effort, you can source a well cared for Odin/Jet combo for less than $200. Get sombody (like rslinger) to tune them up for you and be at least $500 ahead of the game.

 

[rsingler]

That's very kind of you, @Caveeagle
Happy to help the Board!