The difference between octopus and 2nd stage is what?

[Moogyboy]

Octos generally breathe harder and/or wetter in my experience. Probably that anti-freeflow tuning everybody keeps mentioning.

Also keep in mind that a lot of octos are specifically designed to be octos, to wit those miniaturized ones from Sherwood and Genesis. I actually think that they're kinda cool. Wouldn't want to use one as a primary, though. They deliver sufficient air in an emergency, period. I wonder whether the bubble exhaust going straight up over the mask on some of these designed-down regs wouldn't unnerve an already panicky diver more.

cheers

Billy S.

 

[MartijnDorp]

An Octopus is a second stage. The first stage goes on the tank. The second stage goes in your mouth.... an octopus is usually your alternate second stage (alternative air source). What you term your 'reg' is also called your main second stage.

Differences between Octopus (alternate second stage) & Reg (main second stage).

1. Colour: usually bright yellow so that it is easy to find
2. Complexity: usually a simpler version of the main product, or just a different / cheaper product. Although some people are prepared to spend as much on their octopus as their main reg.
3. Hose length: usually has a longer hose length for comfort whilst sharing air. Hose can also be yellow.
4. Breathing resistance: usually set with a higher 'cracking' pressure so that it does not free flow when hanging (possibly inverted) on your octopus holder.

It is important that your octopus matches your first stage and main second stage. This is because different manufacturers specify different intermediate pressures out of the first stage, and also this intermediate pressure can change with operating depth depending on the type of first stage (e.g. over balanced first stage, where the air flow helps keep the valve open once the valve is cracked) This can lead to undesired free flow either on the surface or even free flow at depth if the second stages don't match.

 

[hecker-the-wrecker]

ah why didn't i think of that *doh* the first stage!

i've seen price differences of $335 compared to $100.. the first stage's can be up to $200 alone?

is it possible to just buy a first stage, and 2 "octos"?

There are very few manufacturers that will sell just a first stage by itself. If you can find one, the price is marked up higher than it would sell for if you bought the package. Example; package=$400.00 (first and second stage)
first stage=$325.00
second stage=$225.00
In the end it usually makes sense to just buy the package, in this case you could pay an extra $75.00 and get the first and second stage. I ran into this setting up a pony tank. I was going to buy another first stage, and use my octo. I wound up buying a whole set and keeping the second stage as an extra.

 

[rescuediver009]

There is no difference in the performance characteristics of a primary and an octo. I detune the oct a little when servicing especially if it is of low grade and does not have a venturi lever. Otherise the user will whine all the way home because of a freeflow when they jumped in.

 

[oxyhacker]

If you look in the parts books, you will find that many single-adjustment octopi use a different poppet spring in the octopus versions, to increase cracking pressure and stability. Two adjustment octopuses don't, since tweaking the orifice has the same effect.

 

[fk3lly]

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