Poseidon Extreme Vs. "Standard" design regs

[padiscubapro]

Another issue with the extreme comes to light when your tank pressure becomes extremely low, it is also illustrated when you open the tank valve. At extremely low pressures the second stage has a deisgn that causes a free flow. When opening a tank valve before beginning a dive or even during a valve drill at the end of one this does not present a problem. If however circumstance has presented you with this problem during a dive your small amount of remaining air will bleed out of your tank and leave you with NO air sooner.

Mark Vlahos

Mark This concern can be minimized but not eliminated.. When I dove OC I used Poseidon 1st stages on both posts of a set of twins, One reg had a poseidon 2nd the other a conventional second.. If I got in a situation where the tank presure was going to be that low, I would switch to the conventional reg.. That leaves the only potential problem, if your buddy had to share your gas. and you really had to drain the tank. It is hard to get the reg to freeflow but it IS possible, when this happens simply taking the reg out of your mouth and cupping your hand over the mouthpiece is usually enough to stop the free flow.. Having the second properly adjusted also helps alot.. I always had my regs tuned to work at a lower pressure than normal for some of teh poseidons.. my 1st and 2nd were always tuned to operate ~150psi max..

 

[Greg Barlow]

Mark This concern can be minimized but not eliminated.. When I dove OC I used Poseidon 1st stages on both posts of a set of twins, One reg had a poseidon 2nd the other a conventional second.. If I got in a situation where the tank presure was going to be that low, I would switch to the conventional reg.. That leaves the only potential problem, if your buddy had to share your gas. and you really had to drain the tank. It is hard to get the reg to freeflow but it IS possible, when this happens simply taking the reg out of your mouth and cupping your hand over the mouthpiece is usually enough to stop the free flow.. Having the second properly adjusted also helps alot.. I always had my regs tuned to work at a lower pressure than normal for some of teh poseidons.. my 1st and 2nd were always tuned to operate ~150psi max..

The IP on the Xstream is also to be set at 8.5 bar or around 125 psi. I don't think that the tank pressure issue is of a major concern. If you are breathing a tank that low then things are starting to go pretty bad...

Greg

 

[padiscubapro]

The IP on the Xstream is also to be set at 8.5 bar or around 125 psi. I don't think that the tank pressure issue is of a major concern. If you are breathing a tank that low then things are starting to go pretty bad...

Greg

I should have been clearer in the response thanks.. I meant the OLDER poseidons which some had ips in the 170 psi range and you were able to ocaasionally induce a FF above this point.. the newer ones use reduced IPs like you stated.. If you get it that low, many your REALLY screwed up..

The servo assist in the newer versions appear very smooth but I have never personally tried to use it with a near empty tank to see what happens...

 

[Battlefrog71]

What an excellent discussion. 15 years later and I wander what the market has done. Did it follow the Poseidon’s designs or are they still in the rut of the standard regulators? It’s 2021 and I am asking many of the same questions the OP pondered. Off I go down the rabbit hole.

 

[Lostdiver71]

What an excellent discussion. 15 years later and I wander what the market has done. Did it follow the Poseidon’s designs or are they still in the rut of the standard regulators? It’s 2021 and I am asking many of the same questions the OP pondered. Off I go down the rabbit hole.

The market did not follow Poseidon, most regulators on the market are a conventional downstream design. That being said my Poseidon Odin/Jetstream is still going strong after 25+ years! Poseidon did add an overpressure relief valve to their new regulators so you no longer need to purchase special hoses and many of us have added aftermarket relief valves and adapters so that we also can use regular hoses. The only problem with owning a Poseidon regulator is that not everyone knows how to service them properly but their are plenty of shops that will let you ship them there for service. I have used this regulator down to 150 feet with no problems and will probably buy another Poseidon as my next regulator as I am a fan of the way they breathe.

 

[evandroairton]

When i was diving OC doubles, xstreams were my choice! Still have them, and always performed flawless, to me they are the best!
I have the old in line first on my right and the old 90 degree (no ports up) on left, with hoses built in opção.This way hoses are always down. The mk3 with integrated opv was a clear evolution.
Also used old jetstreams, and love them, and still have a Triton for decoration
Also have apeks, and dive rites, but Poseidon still my choice for tech OC

 

[evandroairton]

Mark,

I know the Poseidon regulators quite well and the latest model (Xstream) is really the best regulator you can take with you under the water for deep diving. It is reliable, strong and has all the benefits of Poseidon's long experience with other excelent regulators, in particular the CYCLON model. In fact, the design of the 2nd stage has always been revolutionary at Poseidon, they never followed the other manufacturers "traditional" design. Poseidon's main characteristic has been the reduced size of their second stage and very solid 1st stages, ideal for diving in cold waters and extreme conditions. Accordingly, Poseidon is used by the German Navy, the US Navy and, of course the Swedish Navy.

Having said that, the only problem you can have (as a owner of a Poseidon) is if you live outiside Europe or North America. Then finding reliable maintenance (for the annual inspection and repairs) for Poseidon in Latin America can be a nightmare and a very costly experience. I am living in Brazil, here it is impossible finding spare parts or servicing for Poseidon. The only other manufahhtcturer in the world following Poseidon's concept and design is OCEANIC, from the US. In fact the OMEGA II model is almost a copy of a Poseidon, both the second stage and the first. I have two OMEGA II (with the DX-4 balanced diaphragm first stage/300 bar DIN). They are excellent and have been produced by OCEANIC, with this same design, for more than 20 years. At the end of the day, the quality of a reg is mesured by each and every diver under the water; when you breath very easily and you don't need to carry a heavy first stage in your mouth, then you know you got a goog regulator. If you want a very good regulator, but you live in a country without Poseidon authorised dealers, then the OMEGA II is the best for you (but you need the DX-4 Balanced Diaphragm first stage/300 bar DIN).

Kleber eu costumava mandar os meus na scubalab. O kit é caro realmente

Their kit is really xpensive here

 

[rsingler]

There is an improvement coming, I'm told. Not any time soon, but Poseidon may be introducing a turreted XStream. Now wouldn't that be nice? The ruby ball, Kevlar diaphragm and a turret? Best first stage in the world, whether or not you use it with a Poseidon second.
There are folks that like the breathing characteristics of the Jetstream and there are those that have this worry about the upstream servo. So mate the first with your favorite second and you have the best system for you.

 

[lexvil]

There is an improvement coming, I'm told. Not any time soon, but Poseidon may be introducing a turreted XStream. Now wouldn't that be nice? The ruby ball, Kevlar diaphragm and a turret? Best first stage in the world, whether or not you use it with a Poseidon second.
There are folks that like the breathing characteristics of the Jetstream and there are those that have this worry about the upstream servo. So mate the first with your favorite second and you have the best system for you.

Probably go well with the 420

 

[Bigbella]

The market did not follow Poseidon, most regulators on the market are a conventional downstream design.

The Cyklon is still live and well, with few changes to the downstream second, since Eisenhower . . .