Mares Abyss 42 vs Scubapro G250v/mk25

[Fishpie]

I loved the 128....a real sleeper.

 

[hg frogman]

I have first hand experience with the MK25/G250. It's a reg you'll never have to trade-in for an upgrade no matter where your diving takes you.

That's almost true. Beware of freezing water, though. But I agree the Mk25/G250V may be OK for cold, but non-freezing, water. It's certainly OK as well for very deep diving, like the Abyss (which went down to -313 meters with Mark Ellyatt).

I already broke the plastic casing of one of my G250Vs, while my full metal Abyss look like they will last longer than me .

The "bypass" of the Abyss somewhat reduces CO2 build-up because it suppresses the dead-air space of the second stage (= the gas flows directly from the hose to your mouth through the bypass).

On the other hand, the G250V, thanks to its dive/predive lever for changing the Venturi vane position, and its knob for increasing the cracking pressure, is more "idiot-proof". I mean with an Abyss there is no such lever or knob, you have to pay attention to the position of your octopus when you enter the water if you don't want to experience a free-flow. But personally I find it easy to handle.

Because of that, the G250V may (theoretically at least) be more suitable for diving with a scooter (DPV). I don't know, I have no experience of diving a scooter with an Abyss (or with a G250V, for that matters). But I never experienced a free-flow from my Abyss (primary or octo) while facing a strong current.

 

[Phil79]

Both great Regs. I have / had them both. My favorite is S-Pro, but the MK17 (dry sealed) with the G 250. As second Reg i use the MK 25 with the G 500. Perfect for me, even in cold water.

I only think that the Abyss (with first stage MR 22) was a little bit more easy to breath.

As i know all these regs are Nitrox ready up to 40 %. In Germany the law says that over 21 is like 100 %. But this is only law and has nothing to do with the regs. If you want to use higher EAN than you have to clean the regs and maybe change parts or you buy a 100 % reg.

 

[Wayne at DiveSeekers]

I'm a fan of the MK17/G250. Since you are looking at the Mares (you like that it is all Metal), and you are not too concerned with how the front cover comes off, then maybe you should look at the ScubaPro MK25/A700. Metal 2nd stage and this thing does breathe really nice.

 

[Phil79]

Very nice Reg - but so expensive!

 

[halocline]

The "bypass" of the Abyss somewhat reduces CO2 build-up because it suppresses the dead-air space of the second stage (= the gas flows directly from the hose to your mouth through the bypass).

No offense, but this is complete BS. You're quoting sales rhetoric. I can't imagine you have any sort of evidence, meaning clinical data, that show elevated levels of CO2 with other regulators compared to this one?

 

[LeadTurn_SD]

No offense, but this is complete BS. You're quoting sales rhetoric. I can't imagine you have any sort of evidence, meaning clinical data, that show elevated levels of CO2 with other regulators compared to this one?

I'm a very happy, and very biased Abyss owner, but I've got to agree with halocline ("The Diver Formerly Known As mattboy" ).

Despite what the marketing gurus write, I don't believe there is enough dead air space in any modern 2nd stage to make much difference, when compared to the anatomic dead air space that exists in each of us between the mouthpiece and our lungs.

I'm convinced the VAD does reduce work of breathing, and may be what makes the Mares 2nd's very good breathing unbalanced 2nd stages. My Mares Abyss uses a much heavier spring than the balanced adjustable Zeagle ZX's I use as backup 2nd's and on pony/stages, but real-world breathing performance is near identical between these 2nd stages (with the subjective "feel" being a bit better with the Abyss).

I still need to do a "face off" between the Abyss and the Scubapro R-109 Balanced Adjustable to decide which my favorite "all-metal" reg is going to be

Best wishes.

 

[hg frogman]

No offense, but this is complete BS. You're quoting sales rhetoric. I can't imagine you have any sort of evidence, meaning clinical data, that show elevated levels of CO2 with other regulators compared to this one?

I wrote that the bypass somewhat reduces CO2 buildup, which just says that : somewhat, which I understand and meant as "a little bit", or "marginally" if you prefer. No need for experimental measurements for that, it's just elementary gas dynamics once you understand how the bypass functions. And I never pretended it made a big difference when compared to other regulators. I am sorry if you imagined something else from what I wrote ; so, corrected I stand .

What I wrote is no sales rhetoric (I don't think that Mares even mention it, I have never read it in their advertising or booklets anyway) but it may be part of the patent (I am not sure). And I still believe, as a D.Sc. and a former researcher in computational fluid dynamics (but not for Mares or any dive manufacturer), that it is a small "plus". But not enough by itself to make the Abyss a winner.

 

[halocline]

I wrote that the bypass somewhat reduces CO2 buildup, which just says that : somewhat, which I understand and meant as "a little bit", or "marginally" if you prefer. No need for experimental measurements for that, it's just elementary gas dynamics once you understand how the bypass functions.

Sorry, it does not matter whether it's "a lot" or "a little"; if you can't demonstrate it with clinical data, you cannot make this claim.

So, until someone does a test which proves otherwise, I'll make the claim that there is NO WAY that this regulator is going to result in measurably lower CO2 levels in the diver's lungs. Period.

If someone from Mares reads your statement, it might yet become sales rhetoric!

 

[h90]

What I like on the Abyss is, that there is nothing to break.....Very simple design, once adjusted well, it works for years without service. it is terrible heavy, but you can use it as hammer and later dive with it, as it is metal. I also have one as octopus and never any problem with freeflow.

I love it, but that doesn't mean that Scubapro is any worse. I never directly compared them.