Should regulators on twin cylinders be absolutely identical?

[waterpirate]

Performance is the issue. If you dive a high performance primary reg and have a failure (like I did) and bail out to a p.o.s. oceanic at tech 2 depths you will regret that decision. Your example should be fine, cobble away.
Eric

 

[dendrite]

That's 9 votes, for "it doesn't matter" or "they're close enough anyway", and 0 votes to the contrary. Thanks for the advice.

Apart from cosmetics, the only reason I could think of was that just that you wouldn't want a breathing difference between the two. It makes no sense to have the alternate superior because you won't use it most of the time, but it makes no sense to have it inferior either because that's the one you'll have to breathe from if you donate your primary.

Oh, and if the first stages were different, they might be different weights and then you'd be unbalanced

 

[Stoo]

I dove for years with two mismatched regulators... Both Scubapros, but many model-years apart...

Tanks pretty much need to be the same as variances in height or diameter can put strain on the manifold, or prevent the bands from holding properly (and so, straining the manifold), but there's absolutely no reason regs need to be the same, as long as hose routing etc. can be managed.

The last I checked, there are no points awarded for "style" in diving. Although sometimes I wonder...

 

[Nasser]

I dive Scubapro regs. Started with just my Mk20 years ago for single tank and then when I started diving doubles I bought an MK25 and upgraded the MK20's parts... effectively making it an MK25. Second stages are one primary high performance balanced and the backup is non-balnced.

 

[scubastingray]

But here's food for thought. One of the most accomplished tech instructors that I know once told me that she recommended specifically choosing two different regs from two different companies (different designs) on each post. This was for two reasons. One, it's less easy to get confused about which reg is in your mouth if a lot of stuff is going on, since you can tell the difference by "feel" (I guess she meant weight or something). Two, if you are in some sort of situation where a second stage is going to fail, it's better to have two different designs so you are less likely to have two failures...

Aren't there only a few different reg designs that have been tweaked by various companies? I understand wanting independent regulators, but when they are both based off of the same model it seems like a moot point. I'm thinking about apeks & clones.

 

[tstormdiver]

You don't need identical regulators, but I would recommend that they at least be comparable. The biggest thing to keep in mind, if they are not identical or comparable, that you are breathing on the primary which may breathe well.... If circumstances dictate that you must do an emergency air share, then you will have to switch to your back- up which may not breathe as easy,.... top that off with a little stress, if it is a real situation & you may have a panicky or near panicky buddy to deal with. Are you comfortable with that? If so,... go for it. Personally I want my back- up to breathe as well as my primary for such situations. I even have identical 2nd stages on my recreational set- up (S600's),... for exactly the same reasons (we must teach donation of the primary regulator).