using octo reg as primary

[cat]

JMHO - this addresses the slightly mutated discussion, not the original question (which seems to have been answered well enough already)

If a reg model isn't good enough to be a primary, do you really want it as an octo?
My octo isn't quite up to my primary but it's still a very good reg (I have the squirrel's setup with an r380 octo). I trade them around a lot on dives practicing drills, etc. They don't breathe quite the same (the octo is lower performance to reduce ff in current and lacks the Venturi adjustment of my primary) but when I ordered the set I reasoned that the octo I bought must be good enough for the deepest, coldest, hardest-stress diving I do because I could end up having to breathe it under those conditions (primary donation). The octo's not quite as good at shoving air down my throat but it's not hard to breathe - don't notice any difference past the first couple of breaths, really, and there's no reason at all that i couldn't dive with both primary and backup R380s.

As it happens - I *did* end up having to breathe my octo under the deep/cold/slightly stressed conditions and was very glad I'd gotten a decent one. (Not sure I'd have cared to do so with a lot of the rental setups I've seen and used - even with the good one that initial switch to my backup in 95' of 39F water was still a bit scary for a newbie like me).

So my suggestion is: go to your octo next time you're down there and see if it's good enough. If it isn't, well...
I think I'd almost rather haul around a POS primary/POS octo pair so the limitation is obvious than get sucked in by a good primary and find myself faced with a POS octo in an emergency.

 

[scubajay]

In that case go for it.

But as I learned the octos are made to breath harder so they will less likely to free flow. Your primary is not likely will fail but that failure would cause an air free flow. Even though you can breath from a free flow (very uncorfortable) it will eat up air very rapidly.

I guess what ever you think will makes you confortable is right for you. I guess you could say that Im going by the book.

Have fun on next dive and I wish there were more caring buddies like you around. I would be your buddy any day.

jay

 

[raviepoo]

...just to reassure myself. I definitely notice a difference between it and my primary, but I've never felt it was a real problem. All regs seem like a POS to me after breathing off my own, sweet primary.

I traded primaries with my sweetie the last time we went diving. I was VERY happy to get my own primary back after that experiment. His reg doesn't suck. It's just that mine is really awesome.

 

[Charlie99]

scubajay once bubbled...
But as I learned the octos are made to breath harder so they will less likely to free flow.

You can still have octo that breathes easily.

There are at least 2 key characteristics. One is the cracking pressure --- the amount of vacuum you have to pull on the mouthpiece before the reg starts to deliver any air. This is generally set higher on an octo.

The other characteristic is the total work-of-breathing. This is how much effort it requires to complete a full breathing cycle. Some cheap octos have very high WOB, even if you set the cracking pressure to 0 ---- the Aqualung LPO is an example of this. No matter how you adjust the cracking pressure, it has a lot of resistance when you try to draw a full breath.

On the other hand, if you take a high performance 2nd stage, and detune it, it will have high cracking pressure, but when you suck a big full breath off of it, it will still come easily.

If you have to use an octo, there is a high probability that the user will be breathing fast and heavy. This is the very last time when you want a high work-of-breathing 2nd stage. If an excited diver can't easily draw a full, deep breath, they are much more likely to reject the octo and bolt for the surface.

 

[ZenSquirrel]

deepwater once bubbled...
Damn squirrel....you've been saving your nuts up for a while haven't you....

....and spent a couple that I have not even found yet....

 

[WaterDawg]

raviepoo once bubbled...
For example, if you go to www.scubastore.com you will see an Apex ATX 40 for 238$. The same vendor sells the ATX 40 Octopus for 142$. This seems like a considerable savings, doesn't it?

It isn't. The difference in price is the first stage. The ATX 40 regulator comes with one. The octopus doesn't. When you buy an octopus it is assumes you already have a first stage.

Thats absolutly right, single second stages are sold as "Octos" I went to the website and that is the diffrence, the "hundreds less" you are reffering to is cause it dosent come w/ a 1st stage.


Its your life down there, dont skimp.

 

[scubafanatic]

.....I wonder what happens when an OOA diver grabs your POS octo, finds it inadequate, and decides they'd rather have your primary 2nd stage?

......or they use the octo, find it inadequate, and bolt for the surface, dragging you up with them?

......or they use the POS octo, find it inadequate, panic, spit it out, and embolize rocketing to the surface?

.......remember, the OOA emergency may not strike when when you're relaxed....it might hit when you're finning against a current or otherwise exerting yourself, as is your buddy....then one of you gets to use the POS octo, which may be the straw that breaks the camel's back.

......personally I can't think of a dumber way to save money.....all my regs have identical twin 2nd stages, a human life is worth the extra $50.


Karl