Advice and opinions: Atomic B2 vs SP Mk25/A700

[South north]

Hello,

I'm a first time poster and starting to feel really out of my "depth" sorting out which regulator to buy. I think I have narrowed it down to an Atomic B2 or ScubaPro Mk25/A700. My dives will be warm water in Central Texas, the Gulf, and the Caribbean. Hopefully Overseas (SE Asia, South America) at least once a year. I have some questions that would help me narrow down my choice though any advice would be appreciated.

1. I've read on the SB that Scubapro has a worldwide network for service, does that provide an advantage to the vacationing diver who is there only for a week or two? (Quality of Service and quick turn around)

2. I have also read because of some feature on the Atomic rinsing the 2nd stage can be difficult, could you elaborate?

3. To any beach divers or central Texas divers should I be concerned about buying an piston first stage and "gunking" it up?

4. I have trouble with dry mouth and have heard that a metal barrel in the A700 alleviates this, does anyone agree and does the Atomic exhibit similar qualities?

Thanks in advance,
David

 

[reefrat]

The B2 and A700/mk25 are both exceptional regulators and you would most likely not be disappointed with either. I did about 250 dives on my B2 and sold it for to pay for an A700 for no reason other than I felt like a change.
The B2 is slightly lighter in the mouth and with the M1 exhaust tee fitted is a great all rounder.
The difference with the A700 is that it has a metal body second stage, which does add a little moisture to the inhaled air, but mostly it's just very big on "cool' factor (nothing wrong with that)!
The only functional preference I had in regards to the A700 was the user selectable venturi, if you plan to switch second stages under the water a lot this is a big deal, but if you are the average recreational user who rarely takes the reg out of your mouth- not so much!
If you are concerned about contamination in the first stage then get the A700/MK17, the flow rates from this first stage are head and shoulders above any other diaphram unit, but maybe way more than you would ever need!
As an aside I have re-furbished my older Mares MR22/Abyss and find I am using that most of the time now.
In the end most modern high quality regs are able to cope wih anything you will throw at
them and really, provided they are well tuned and you have a good mouthpiece + hose fitted you will be happy, unless of course your search for the "ultimate" reg is part of an on-going diving obsession (once again, no problem with that!).

---------- Post added April 24th, 2012 at 06:07 PM ----------

Whoops, the rinsing thing with Atomics!
If I had to rinse my B2 second stage unpressurized I always wound in the cracking pressure adjustment a few turns first to seal the low pressure seat and then gave it a wash (remember it IS a titanium component system and should not need too much cleaning after every dive).
Then I hung it with the first stage up high and the second below so that any water wouldn't get to the first stage.

 

[South north]

Thanks for the Reply Reefrat,

You have really helped me clear some things up. Just to be clear the A700 has added a little extra moisture to your air compared to the B2. Does the B2 offer any moisture? or how does it stack up against the A700? Do you think I should be concerned about servicing my regulator while traveling?

BTW, I had the chance to handle the A700, I agree the regulator is pretty damn cool, and there is nothing wrong with that!

 

[diversteve]

They're both so close but my guess would be that the B2 is slightly more comfortable. The B2 2nd stage is slightly lighter - having the swivel makes it a lot nicer. I have one on my T2 and will never buy another reg without one. Atomic also sells a universal swivel hose if you want to add it to the Scubapro. Every Atomic breathes the same, the difference is in the materials used.

Really though the breathing is about the same. I used to have a dealer who sold both Scubapro and Atomic so I've tried the best of both in their pool. If there was a difference I couldn't tell. I bought the T2 because it's all Titanium - and I could. Before that I had a B1 that was bulletproof - never did anything but recommended factory service every 2 years. Most times the tech told me he only changed the parts since he had it apart anyway. I think the seat saver orifice contributes to that - downside is it causes the rinsing issue previously mentioned. I only learned about that after I bought the T2 so my B1 went through years of normal dunking w/o any apparent problems.

I've recently read that unless you buy a whole pkg. from Scubapro, (reg, BC, suit?) that they aren't offering Free Part for Life anymore. Although that's not really a factor, locally I pay $60 parts/labor to service my Atomics.

 

[South north]

Hello Diver Steve,
Thanks for replying to my post. To be clear what are your comparisons between the A700 and B2? (Moisture and general impressions). What are your post dive regulator rinsing procedures? (specifically the B2). Big thanks for the advice on the swivel for ScubaPro though you might have made my decision more difficult!

 

[eelnoraa]

I am using T1 1st stage, B2 2nds for single setup. And I use Mk25 1sts and B2 2nds for double, so the only thing I haven't used in your list is A700 2nd. So I cant comment on the moisture difference between B2 and A700. But since B2 also use a metal barrel (titanium), so I kind of think this aspect should be the same tween them.

From first stage point of view, I prefer Atomic over Mk25 for 1)Atomic is lower profile, both shorter and protrude less from the valve. If can be a better choice for travel and also less likely to head you head. 2)Atomic is or at least can be sealed. I don't know how much difference this makes, but in absoulte sense, sealed is still better than non-sealed.

From overall system point of view, I also prefer Atomic mainly because of its bi-annual service interval.

As for rinsing atomic, I haven't really pay too much attention about it. But I always connected the reg to a tank after washing and purge the reg. Atomic B2 is made of Ti, so I guess it is not as suceptible to a little flesh water.

 

[South north]

eelnoraa,
I really dig your handle name. Thank you for your comment on the B2 having a metal barrel, now you have tipped the scales and made my decision that much more difficult! Your setup for doubles are first stage Mk25 yet you recommend the Atomic second stage. Your single setup is all Atomic. What would you recommend in buying my first setup (with the possible move to doubles)?
Thanks

 

[diversteve]

I may not have tried an A700 at the time, it might have been an S600. But it was a Ti Scubapro - not sure if they still sell it. As I mentioned the breathing was indistinguishable, the overall perception I had of the 2nd's was that the Scubapro was slightly bigger and bulkier. But if you like the look better, buy it - I almost did. I think in the end the 2 yr. service interval for the Atomic is why I chose it.

To rinse mine I either clean/purge the 2nds while still hooked to a tank (not always doable - but I managed on a liveaboard) or I keep the 1st stage higher than the 2nds while rinsing in the tank then drying - when I remember. Screw the dustcap down tight (it's rubber) on the 1st stage and dunk it separately. To be honest, reg maintenance isn't one of my better skills so in a week of liveaboard diving I'll probably do it once at the end of the week. On shore dives I rinse them every day as most of my dives will be off sandy beaches somewhere warm. Occasionally I do "valet diving" in which a crew member takes care of our gear at the shop/boat during the week. I never remember to tell them so my regs are likely subject to the same dunking as everyone else's.

 

[Kunundrum]

Both are high quality regulator, the Atomic would be my recommendation in your specific case, mainly the seat saving orifice will take the pressure off the low pressure seat when not its not in use. (especially beneficial in long storage situations) ensuring the regulator keeps working properly when not used for long periods of time.

The B2 is a Great regulator, that being said I do prefer the ST1 it's superior corrosion resistance and harder material ensures a long life even it it were to get abused and neglected. It's only a little heavier than the T2x yet half the price.

In a pure salt water environment and occasional diving, the ST1 is a winner in my book.

 

[Islandheart]

I've owned both of these great reg sets and many others....

That said, the Atomic is slightly better from a user stand point, not based on machine testing. Please don't think the A700 is a "Wet" reg, it is not.

just make sure you always drink a bottle of water before every dive.... helps keep you warm too !

Don't sweat the rinsing thing, do pay attention to the nice swivel on the Atomic and a MAJOR advantage is the 2 year service interval on the Atomic which saves $$$.

I'd take the comment above to heart and reach a little higher for the ST-1 vs the B-2 (the saving on service will easily make up the difference)....

Don't get me wrong, I like the Scuba Pro Regs but the Atomics are the cat's meow !