Alternate Second Stage Quality

[djhall]

I have seen several places in these boards where people strongly assert the need for the primary and alternate second stages to be of comparable performance and quality. I have not seen what I feel to be a good justification for why this is necessary. Perhaps I am simply misunderstanding what is meant by "comparable".

I have always believed the alternate second stage is only intended for use while assisting an OOA diver or in the event your primary second stage fails. In either event, the appropriate response is to immediately end the dive in the safest manner possible. This would seem to imply that the alternate secondary stage 1) will be used infrequently for relative short periods of time, and 2) needs to be in good working order whenever it is required. I would hope almost any currently or recently manufactured regulator of reasonable quality which has been properly maintained would be capable of satisfying this need. I would be justifiably and understandably upset at myself or someone else if, during an emergency, the needed alternate second stage was not functional due to neglect. But has anyone ever surfaced from an emergency requiring the use of the alternate secondary and said, "Hey, thanks for the help, but your octopus has a little harder cracking and sustanining effort than I like, and it breathes a little wet, which I found kind of annoying?" If anyone said that to me, I think I'd let the ungrateful SOB drown the next time they got into trouble!

Can anyone explain to me why the regulator configuration I am preparing to use - ScubaPro MK25 first / S550 or S600 primary second / R190 alternate second - would be inadequate for standard, recreational, open-water diving above 130 feet? I don't believe the S550/S600 is "comparable" to the R190, but I also don't see why it would be inadequate for use as an alternate second.

 

[MikeFerrara]

I hand off my primary and have no desire to use a lousy breathing regulator especially when bad things are hapening and I may be working hard. Are you looking to save money?

Stress, hard work and a lousy reg is a combination that should be avoided.

Using real second stage for an alternate has the added advantage of giving you an extra second stage that can be used anywhere. For instance if you decide to use a H or doubles valve all you need is another 1st stage you heve all the second stages you need. If you had purchases one of those lousy alternates you still need another second stage and you will have an alternate sitting in the drawer never to be used again.

 

[redacted]

Its classic downstream design is not going to breath as well as the balanced barrel poppet design of the S550 or S600. After detunning for octo use you may well be able to tell the difference at depth. But you will probably have to think about it and it should not be discomforting. With that Mk25 rather than the usual Mk2 associated with the R190, IP will stay constant so that source of noticable performance decrease is not present.

As another recreational diver, I agree that when the octo is forced into use, it's only for a safe trip to the surface as that dive is over. I think your plan makes perfectly good sense. Definately can't see throwing another $100.00 or more into a high end 2nd for use as a recreational diving octo.

 

[MikeS]

I wouldn’t dive with an octopus that I wasn’t willing to dive with as a primary. I also insist on a full size spare tire!

Mike

 

[wetman]

You can compromise here - get a top quality primary and maybe a less featured top quality backup. I've got an apex 200 as my primary 2nd which is smaller and offers adjustments. I've got an apex 40 as my backup which is also a great reg its just slightly larger and does not offer some of the adjustments which IMO makes it slightly more robust (i.e. not as much could fail which is nice in a backup). Either breathes extremely well.

steve

 

[Genesis]

A Scubapro MK25 first with an S600 as my primary and an R380 as my backup.

The latter is on a bungee around my neck. If you need a reg, you get my PRIMARY, and I get the backup.

I have retuned the R380 from its "as sold" octo detuned config to be fairly (but not seriously) aggressive - since its under my chin it isn't exposed to nearly as much water pressure and its freeflow propensity is pretty much non-existant.

I'm happy with the 380 and have no problem breathing it myself.

 

[ericfine50]

I use two Tx-50s for my regs. That way I am breathing a very good reg if I need to donate. I don't want to be sucking hard in a stressfull situation. And as stated above, you have a spare if needed.


Eric

 

[Norm]

While it's true that almost any second will work for shallow recreational sport diving, I hold/teach with the school that:
Your octopus should breathe at least as well as your primary.
If you (or your buddy) ever needs it you may already be under an immediate stressful situation. No one involved needs any additional stress at that point! JMO
Norm

 

[SimonN]

Although PADI teaches to go for the occy, in reality when the brown sticky stuff goes flying you may well end up breathing the crap occy you bought to save money.

This is really to point out to people that maybe buying a really crap occy (you know, the kind which are hard to breathe on the surface let alone at depth) is a bad idea.

However, the R190 is a good reg. Not as good a breather as the S600/S550, but simple and effetive. FWIW I would happily dive one to 50M on air or any depth on mix - I use an R380 (basically an R190 in a smaller package - kind of) as my backup reg, so kind of have. And, I can't really tell that much difference between it and my G250 primary!

Another thing to consider is keeping spares. If you have the same second stages as primary and backup, you only have to keep one set. (A good reason for Apeks DS4s and ATX40s).

 

[Compressor]

Is Air2 an option?


I find its short hose very handy. Hand the primary reg over, grab teh air 2 and go for the surface. Never done it from deeper than 100 feet.