Cold water: Does 2.stage matter?

[eelnoraa]

While I do agree 2nd stage is important, but z3 2nd stage is NOT any inferior to ATX 2nd stage for cold water. The inlet tube is brass and casing is plastics, exactly like ATX. Either one should be reasonable good.

 

[eelnoraa]

Thanks for all. Apeks DS4 first and atomic z3 second did fine yesterday. 6 celsius water

6C isn't all that cold. It is 43F. Your z3 first stage would have been fine. In location I dive mostly, plenty of divers use mk25 in winter at low 40s. I think the cold water reg thing requirement is really over blown

 

[Dominik_E]

To the very best if my knowledge, the Atomic 2nd stages are exactly the same whether you buy a "cold water" (sealed) Z3 regulator set, or a warm water version. The relevant difference is the Christolube - packing of the first stages. I do dive a Z2 second stage in cold water, and as of yet never had troubles. 6°C actually is already quite cold. It takes quite extraordinary circumstances to have fresh water cooler than 4°C at depth (--> density maximum for water!). I therefore think you will be fine with the combination.

 

[ams511]

Yes, the second stage matters. I've seen more second stages let go whien diving in cold water than first stages. I've also seen more ice build inside second stages than around first stages. In y view, the second stage is just as important as the first when it comes to cold water diving.

But how many cold water second stages are there? AL has the Glacia (Arctic before that) which is now discontinued. Sherwood has the Blizzard which is a mild modification of the Magnum. Scuba Pro used to have a specific cold water reg (M2?) but discontinued it years ago. Most others manufactures say their top of the line regulators are cold water capable.

 

[JackD342]

But how many cold water second stages are there? AL has the Glacia (Arctic before that) which is now discontinued. Sherwood has the Blizzard which is a mild modification of the Magnum. Scuba Pro used to have a specific cold water reg (M2?) but discontinued it years ago. Most others manufactures say their top of the line regulators are cold water capable.

There is an undefined difference between a cold water regulator, and one designed for extreme cold water. Cold water is generally considered to be below 50F. In my mind I would strongly consider an “extreme” design for below 38 or 40F.
And Mares Navy II is a major player in that space, at least for the USN.

 

[shurite7]

But how many cold water second stages are there? AL has the Glacia (Arctic before that) which is now discontinued. Sherwood has the Blizzard which is a mild modification of the Magnum. Scuba Pro used to have a specific cold water reg (M2?) but discontinued it years ago. Most others manufactures say their top of the line regulators are cold water capable.

Scubapro has two really good cold water second stages: G260 and A700. Apex second stages hold up quite well in cold water. Poseidon's X-Stream is also a very good for cold water reg. I list these based off of first hand experience or at least diving next to someone with one of regs. I view cold water as anything in the 30's (although I am beginning to feel like anything in mid to low 40s is cold); for ex. winter in mountain valley lakes and diving underneath the ice. Not sure if I agree with the term "extreme cold", unless it is in the high 20's, as in Antarctica.

 

[Centrals]

I bought Apeks atx first stage with two DS4 second stages. I would prefer my atomic aquatics Z3 second stage because it have this swivel. Does second stage matter when diving cold waters? Or is it all about first stage which matter?

DS4 is cold water 1st stage.
For ATX 2nd stages only the 20 is NOT compatible with cold water
You can add the heat sink and the adjustment screw if you can find the respective parts.
For Apeks cold water means under 10C(50F).

 

[buddhasummer]

Have to wonder how much difference it actually makes whether the jam nut is plastic or metal.

 

[eelnoraa]

Have to wonder how much difference it actually makes whether the jam nut is plastic or metal.

For Atomic, I don't it makes no difference down to 40F under normal usage. I used a B1 2nd stage with plastic jam nuts. Used it for years in Monterey, which can get to low 40s. Never had issues. I only upgrade to old style M1 heatsink only because I bought 3 for $5 at a closing dive shop.

I have to say 50F/10C is surely not cold water for regulators. My first reg 2nd stage is Hollis 212s. All components are plastic inside. Lousy 2nd stage, but I have not gas freezing issue Monterey down to low 40s either.

 

[ams511]

There is an undefined difference between a cold water regulator, and one designed for extreme cold water. Cold water is generally considered to be below 50F. In my mind I would strongly consider an “extreme” design for below 38 or 40F.
And Mares Navy II is a major player in that space, at least for the USN.

I am not all that familiar with the Mares line but I thought the Navy was their top-of-the-line model. Also what is the difference between the Navy II and the Abyss 22?