What makes a 2nd stage better than an octopus?

[Externet]

Hi all.
Prices of comparable second stages and octopuses differ; what makes the difference? How safe is to use an octopus as primary regulator? Do all octopuses have the hose inlet on the left side ?

Came across a cheap second stage almost identical to a "Promate Hydro Wizard Octopus
OC500" as shown at the end of page here:
http://www.promateusa.com/regulators.htm

With another passage pattern on its front; cannot discern brand, has no markings/logo which seems unusual for a manufacturer not to mark anything. Is it a chinese something ?

It has the hose entering its right side, as a main second stage. What is it ?

Miguel

 

[The Chad]

IMHO an octo is not safe to use as a primary diving reg. unless you enjoy CO2 build up and headaches. When someone swithes to an octo or needs the air from one the dive is over in my book.

 

[DougNR]

Since you seem to be refering to second stage / octos other than the low profile type, I think the general answer to your question is an octo is simply a de-tuned seconds stage with (usually) a bright colored face and of course a longer hose.

I see no reason why you couldn't use a re-tuned octo assuming it was checked out by aqualified tech knowing what your itentions were. I agree with a previous comment that simply using an octo as a primary breather is not a good choice.

 

[DA Aquamaster]

I agree that most companies use an octo that is essentially one of their primary second stages that is detuned slightly for increased freeflow resistance with a yellow cover. In some cases there may be minor mods to aspirator ports, etc. that are usually able to be undone by the tech.

The OC600 looks like the same second stage sold by Genesis and also by Aqualung as the Micra. They were quite good second stages when configured as a primary.

I would not personally use the OC500 even if it were free. The design is just not ammenable to decent performance no matter how it is tuned and I think it would have limitations in terms of flow rate and inhalation resistance, both of which can and will lead to CO2 buildup under heavier work loads.

CO2 buildup is associated with increased susceptibility to nitrogen narcosis as well as increased risk of oxygen toxicity.

 

[hamsiss]

DA,
What about Apeks Egress as an octo?
Also about Oceanic Swivel180?

 

[Walter]

An octo is a second stage.

 

[Toolbox-13]

I personally use the same 2nd stage as a octo. I dive Apeks TX-50 second stages with a DST 1st stage so If I give my primary to a buddy I'm breathing the same reg as my back up

 

[m3830431]

DA,
What about Apeks Egress as an octo?

PNEUMATICALLY BALANCED 2ND STAGE includes egress
All Apeks second stages feature a Pneumatically Balanced Valve System. In most second stage designs, the inhalation effort of the diver opens a valve inside the regulator that is held closed by spring tension. In the Apeks pneumatically balanced design, the pressure on the second stage valve is "balanced" by allowing medium pressure air to pass through to the opposite side of the valve to help counteract the force of the spring. This reduces the inhalation effort required to open the second stage valve and substantially improves the overall ease of breathing in all diving conditions.

 

[DA Aquamaster]

DA,
What about Apeks Egress as an octo?
Also about Oceanic Swivel180?

The swivel on the Oceanic and the 120 degree layout of the Egress make them better suited to air sharing on a short hose where the combination of right angle and short hose would otherwise make it hard to keep the octo in your mouth if you are the OOA diver.

The downside of any compact octo is that they are compact and consequently incorporate a very small diaphragm, and in most cases a very small exhaust valve. And generally speaking, they tend to have a lot of bubble interference. Both limit performance whether they are balanced or not.

In general I prefer:

1. To have a back up second stage that is equal in quality and performance to my primary. 2 out of 3 times in a real OOA situation, you will get mugged for your primary and it will be you who ends up using the octo. Plus, even if it goes as planned, do you want a semi panicked very OOA and out of breath and oxygen debted diver having to share air off a poorly performing octo? Both are reasons I prefer not to detune octos - they need to be able to deliver peak performance just like your primary.

2. To donate the primary and to use a long hose primary. The donate the primary approach is better adapted to the real world and the long hose accomplishes everything a swivel will occomplish with the added flexibility of giving the divers more room to swim or ascend in formation. And if the diver is a bit panicky or lacks bouyancy control, you still have the option of holding onto each other's BC as you would in a short hose air share.

If money is a limitation, consider buying a good used second stage from a company with a history excellent support for old and/or discontinued regs such as Aqualung or Scubapro. You could get a first class second stage for the same or less money than you would spend on a new octo.

 

[Fish_Whisperer]

An octo is a second stage.

THANK YOU!!! The question was confusing me... :light: