Octopus and Safe Second

[Alexisdog]

I am curious for some feedback on the idea of diving with both a second stage alternate air (hose attached to primary) and a safe second (attached to BCD inflator).

My thinking is it would seem like a backup, while also 3 can breathe directly in the case of a bizarre emergency.

Most of the discussion I see is of alternate air vs safe second, but I do not see talk about using them together.

 

[clownfishsydney]

Same thing aren't they? In Australia we would call both an octopus. The BCD inflator one has fallen out of favour over here, too many shortcomings with them. I have never seen anyone with both I think.

 

[Alexisdog]

Same thing aren't they? In Australia we would call both an octopus. The BCD inflator one has fallen out of favour over here, too many shortcomings with them. I have never seen anyone with both I think.

Correct, in that they serve the same purpose. But, is redundancy a bad thing? Does anyone do this? Is there any reason not to dive both?

 

[ChrisMBC]

No reasons that diving both would be unsafe, although you do put yourself at higher risk of a freeflow, and more confusing buttons on your inflator for you (or a buddy) to confuse during a high-stress emergency.

Some practical reasons not to:
- Additional cost/difficulty of servicing every year
- Another reg that can malfunction/free-flow causing you to call a dive early (happened to me with a safe second)
- Confusion with a dive buddy over which to go for in the case of an emergency

If you're set on this, the one setup I *have* seen is:
- Primary on a long(ish) hose
- Safe second on BCD
- Regulator on a pony bottle (slung or backmounted)

Then at least you have redundant air for your three redundant second stages

 

[AJ]

Correct, in that they serve the same purpose. But, is redundancy a bad thing? Does anyone do this? Is there any reason not to dive both?

Ask yourself: how long will your air last while three divers in stress (double the SAC, maybe triple it) are breathing form one tank? Then ask yourself: would two backups provide any advantage?

 

[rongoodman]

Don't bother, just get a good secondary of the same quality as your primary second stage.

 

[napDiver]

I'm sure everyone will chime on the cons and i agree it isn't the best choice most of the time to do this.

When i do recreational diving i prefer to use my FFM. In this case, i will have my safe second bungeed to my neck in case i need to bail on FFM underwater. Of course, this means i need to have an "octo" available to donate to others. It works just fine this way and makes the safe second less available to other divers to try to grab it. Another bonus is the safe second will sit more consistently in the same place to use it to inflate/deflate. Now the corrugated hose will need to be proper length which means you likely need to extend it to the original length.

Sometimes I ditch my FFM, but don't want to remove the FFM hose. At first i used to put two second stages and have my safe second. That was okay, but i found it was just easier to bungee my short hose for a second stage to my tank. I have a quick disconnect so the hose is by itself. And just use a "long hose" (at least donation capable length of 40" up to 2') and have my safe second bungeed to my neck. So if i donate, follow a primary donate and put my safe second in my mouth.

 

[AfterDark]

If my experience is typical then don't bother, there has been only 1 time since 1968 that I've used/needed a safe second, a backup isn't necessary. I do bring a complete second regulator set up that lives in my gear bag.

I did consider using a BC/reg device on a ID setup I use but decided against it because of the maintenance it would add and I already have any number of second stages to use instead.

 

[lexvil]

it can be done, no real down side.

 

[davehicks]

I am curious for some feedback on the idea of diving with both a second stage alternate air (hose attached to primary) and a safe second (attached to BCD inflator).

My thinking is it would seem like a backup, while also 3 can breathe directly in the case of a bizarre emergency.

Most of the discussion I see is of alternate air vs safe second, but I do not see talk about using them together.

If your combo reg / inflator dies you may loose use of your BC due to the compromises of these units.

There is a section on this topic in this article:

Info - How to Choose a Regulator

How to Choose a Regulator (an overview of features and their value) One of the first pieces of equipment that every diver will acquire is a set of Regulators. This is one of the most critical pieces of your gear as it enables you to breathe underwater and are considered to be life safety...

scubaboard.com