Octopus recommendations

[rescuediver009]

My thought on octos is that they should be of equal quality to your primary second stage. Most likely you will be the one using it as even if you don't believe in donating your primary, odds are you will get mugged by the OOA diver and involuntarily donate the primary anyway.

Many second stages have flow vane adjustments knobs or dive/pre-dive switches that when set in the (-) position will not support a freeflow. Other second stages have adjustment knobs that can be tightened to de-tune the second stage to reduce the chance of a freeflow but still enable the beathing resistance to be lowered when you are using the second stage.

These are far better options than going with an inexpensive cheaply made non adjustable octo that breathes like a rock and may not deliver adequate air at depth.

I don't think that that there is anything in there I didn't agree with. You always want the octo to be a good performer and know that it has features designed to prevent freeflow. I don't think that there is anything more simplistic than the venturi lever to solve this.
I think that it is a small price to pay to feel secure using your octo and knowing that it will be there. There is no sense on having something that you are using as your backup, but it doesn't perform as well as the primary that you are using. Think about that for a second.

As for what opinion girl had to say, this may have formerly been the case, but modern octos are designed to have the same features as the primary so I do not believe this is true any more. They are just slapped with a different colour, and in some cases a smaller exhaust tee.

 

[DA Aquamaster]

The major difference in most regs between the primary and the octopus is...

THE SPRING!!

There is a stiffer spring on the octopus which will make it breathe "harder". This is to reduce the amount of free-flow. The conshelf is an excellent example - hardly a difference between the octo and primary, except for that spring. The body, and internal parts besides this spring are identical to the primary in most regulators.

Today, Octos with adjustability are easy to find, making it unnecessary to pile a ton of money into a backup primary. Yes, the el-cheapos will breathe stiffer than your primary (but you can tune that to some degree) but will still undoubtedly provide an easier ascent than buddy breathing...again - technical divers will be under a different set of requirements, but a good 'ol standard octopus is more than adequate for a recreational diver.

In many cases it is not the spring that is different but rather the adjustment specifications. Often an octo will be adjusted to offer a cracking effort .5 to 1.0 inches higher than an identical second stage set up as a primary to minimize air loss due to unintentional freeflows. Often the only difference is the color of the purge cover.

 

[opiniongirl]

In many cases it is not the spring that is different but rather the adjustment specifications. Often an octo will be adjusted to offer a cracking effort .5 to 1.0 inches higher than an identical second stage set up as a primary to minimize air loss due to unintentional freeflows. Often the only difference is the color of the purge cover.

I guess it depends on which regulator you are speaking about. With the brands I am familiar with and service, it is the spring which directly affects the effort.

 

[rescuediver009]

I guess it depends on which regulator you are speaking about. With the brands I am familiar with and service, it is the spring which directly affects the effort.

I would like to know which these are as I have never seen that.

 

[opiniongirl]

I would like to know which these are as I have never seen that.

Aqualung, zeagle, genesis, oceanic...I would likely say all of them, but these are the ones I have serviced for years. As well, I believe that there is a description of this in the Encyclopedia of recreational diving.

 

[rescuediver009]

Aqualung, zeagle, genesis, oceanic...I would likely say all of them, but these are the ones I have serviced for years. As well, I believe that there is a description of this in the Encyclopedia of recreational diving.

I am not a genesis man myself, but I can verify that the oceanic, zeagle and older Aqualung regs have springs with the same tension. Especially the zeagle as the reg is the exact same just with the different cover. That is why alot of companies advertise that octos 'have the same great reliability'.

 

[DA Aquamaster]

I guess it depends on which regulator you are speaking about. With the brands I am familiar with and service, it is the spring which directly affects the effort.

The spring compression does directly effect the cracking effort on most second stages due to how the various forces are balanced. However it is most often the orifice adjustment that determines the amount of spring compression. The spring itself is physically no different on a given second stage whether the cracking effort is 0.8, 1.8 or 2.8 inches of water.

 

[opiniongirl]

Hmmm...have to disagree with you then..crappy and older regs (usd, and others as previously mentioned) there is a difference in the springs, ergo a color difference between them (red for octo) so as to distinguish.

I notice you are a scubapro tech - perhaps its different with scubapro. I did mention that this is not a blanket statement, but rather for the brands that I am familiar with.

 

[bottomrunner]

I know that this may not be the best place to debate it, but evertime I see a guy with a pony that he never uses, and keeps it as 'reserve' I want to crack it on his head. I couldn't justify $500 CDN for the unit to sit there. If you are going to have it at least take it into account for your final ascent on your last dive. I think that a bungeed octo that is properly tuned is alot more sensible.

i had a reg that failed closed with 2500 psi. on the pressure gauge
at 60 feet
thank god for the pony bottle
i think my life was worth the cost
back up, back up, back up....

 

[rescuediver009]

i had a reg that failed closed with 2500 psi. on the pressure gauge
at 60 feet
thank god for the pony bottle
i think my life was worth the cost
back up, back up, back up....

I have never heard of a reg that has failed closed. There is only one that will do it, which did you dive with? Firstly 60 ft, is not an unreasonable free ascent depth, but more importantly, all regs are designed to fail open.Anyone that knows anything about regs will tell you that. And if you are diving solo you are also following a different set of protocols..