Difference betwen Octo and 2nd stage?

In looking online at the various regulators for sale, I can't help but ask, "Can an octo 2nd stage be used as the primary 2nd stage regulator?" Is there a structural difference between the octo rig and a dedicated 2nd stage regulator?

recess:

In looking online at the various regulators for sale, I can't help but ask, "Can an octo 2nd stage be used as the primary 2nd stage regulator?" Is there a structural difference between the octo rig and a dedicated 2nd stage regulator?

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Shouldn't be if same make and model. plastic maybe a different color.

Welcome to the board.
Octos are often lower performing second stages than the primary, it's not a requirement but is most often the case. Some octos are nothing more than the same second stage as the primary with a different color cover- these will likely perform as well as the primary assuming the tech who set it up tuned them the same, other times they are totally different. Can you use one for the other? Well yes, but if it is an inexpensive second that is sold as an octo it is likely a pretty poor performer and you will not be happy with it. Some of us prefer to use octos that were intended to be a primary second stage and are close to if not as good a performer as our primary. In an out of air (OOA) situation, it's not the time to have a crappy reg in your mouth.

I've been told that the octo's are less sensitive so that they dont free flow as easily, if you take your main reg out of your mouth and hold it "up" alot of times it will free flow, the octo's dont do this as easily. Anyone, correct me if this is wrong, this is just what I have been told

Each of your two second stages can be any model and color you desire. Breathing effort, size, cost all play a part in that. One of my regs uses the same model of second stage for both the primary and the octo. Many choose to have a cheaper, somewhat lower-performance octo.

See this thread started last week for discussion and light-hearted comments on the terminology and choices.

-Bryan

Thanks for the welcome. I started my diving back in 1969, certified in 1977, and actively dove up through 1986. Well, now with the kids off on their own, wife and I decided to go back and enjoy the beutiful sights we enjoyed in the Fla keys. Will also do some local diving in the Outer Banks NC off our own boat. Nothing deeper than say 30'. We never had octo rigs, or BC's for that fact, but just the old yellow inflatable flotation collar. My original regulator was a Healthways Scubair J-valve that served me well until it disappeared on one of our moves. I've researched the forums, and ebay to see what is actually out there and the options seem endless. The octo thing had me wondering since there seems to be many out there, just wasn't sure of the "quality" thing. I am leaning toward ScubaPro as they seem to have been around since I started. Usually a good sign.
Thanks again for the welcome.

Welcome Recess. My Alternate 2nd stage is actually the same regulator as my Primary 2nd stage, but with a yellow, slightly longer hose, not black. Yes, I have my Alternate tuned ever so slightly for more resistance to limit free flow possibilities. (I do dive in cooler water in Canada.)

As you look around the board you will find a LOT of opinions on gear and recommendations. There is both a lot of good reading, and a few over-passionate posts - as always, read with a grain of salt, but there is a lot of great information on Scubaboard!

bill-da-ho:

I've been told that the octo's are less sensitive so that they dont free flow as easily, if you take your main reg out of your mouth and hold it "up" alot of times it will free flow, the octo's dont do this as easily. Anyone, correct me if this is wrong, this is just what I have been told

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This can be one of 2 things. The less expensive second stages that are sold as "octos" tend be lower performing than a good "primary" so most do breath harder than a quality primary. The other possibility is a higher performing reg that has been detuned a little to help reduce freeflow. Many (most?) techs will detune a octo a little unless told otherwise.


Welcome back to diving recess. You will find the performance of modern (late 60's on) regs will be a lot better than your old Healthways.. I have a couple of them..
Most any of the current brands/models are quite good. Obviously some are better than others but pretty much any brand name mid priced regs will do nicely for many years. Service on the reg would be my main concern. Some of the better know brands like Scubapro and Aqualung may be a little easier to get serviced all over the world and if your LDS goes out of business, it's likely there is another dealer not too far away. The same can not be said for some of the lesser brands. Check to see what brands are serviced by the shops close by you, then choose a brand that several of them support.