A little regulator question

[avengerki]

Ok I am a new diver, just finished the pool portion yesterday and still need to do my open water dives. I have the opportunity to get a bcd(Aqualung Latitude), regulator(Apeks AT20), dive computer(Mares black passion nemo) along with a semi-dry suit, undergarment, fins, mask, boots, dive knife, flag, a couple of bags, a couple pairs of dive gloves and some other odds and ends cheaper than I can get a used bcd and regulator set from my lds.

My main question is researching the Apeks AT20 I see that it is designed for warm water while I will be diving in the pacific northwest primarily. What types of issue can I get into using a regulator designed for warm water? If I replace the 1st stage with one designed for cold-water would I still be able to use the second stage?

My original plan was to get this, resell the pieces I don't need/fit and upgrade the various parts over time, along with using this on my certification dives.

 

[elan]

Your plan is going to be expensive

Just buy the gear you need from the first try. Do some research here and you can get a plenty of advises.

The regulator you have mentioned is not a good option for the cold water. There is a great chance for it to start freeflowing. The first stage replacement does not give anything as the second will be freezing up. From the Apeks family I would take an XTX50/DS4 Or DST

 

[avengerki]

Thank you Elan. My killer deal is now not so killer. I work with compressed gasses so understand about the compressed gasses and freezing but for some reason was thinking the issue would be in the first stage and not the second stage now that I think about it and looked at diagrams I can see the second stage issue. My plan was always going to be expensive in the long run but this way I could get most of my equipment at a price the wife wouldn't gripe at me about, she already doesn't like how much I have spent to take the classes with the price for this just squeaking by her comfort level, and still have everything I need for my own kit. I guess I will need to do some more cost analysis on this but for now I am trending torwards no.

My coworker who used to dive in the past didn't realize there was a difference between regulators and used his in cold and warm without issue but don't know what that model was either. Just glad I asked for others opinion.

 

[Mr Carcharodon]

It would be good to ask how cold the water has to be to be "cold water" for the regulator. I can't actually give an exact answer but in Southern California the water routinely gets down into the low 50F and sometimes into the the high 40F and no one worries about cold water regs. I suspect the pacific northwest is colder, but not a lot colder.

 

[avengerki]

So my instructor did an OW cert last week and it was like 51F where they dived and the AT20 is 50F and up so I could be fine for most of the time.

 

[KD8NPB]

XTX50 + drysuit investment.

 

[Robert Gillcash]

It would be good to ask how cold the water has to be to be "cold water" for the regulator. I can't actually give an exact answer but in Southern California the water routinely gets down into the low 50F and sometimes into the the high 40F and no one worries about cold water regs. I suspect the pacific northwest is colder, but not a lot colder.

If you go a bit further north from Oregon, up to Seattle area or B.C., it can get real cold in winter. I've done dives there where the water was warmer than the air, and the water temp was about 3C (38F)...so yeah, it's cold.
You know it's cold water diving when you get a day where the water is 6c (43F) and you say "Ya! It's warm today!" and get excited!

 

[TSandM]

It really depends on a) when and where you are going to dive, and b) how killer the deal is on the equipment. It might very well be that you could just turn around and sell the Apeks regs and buy something better for cold water, and still come out ahead. Or, if you primarily intend to dive in the summer, you may not really need cold water regs.

I dove ScubaPro MK25/S600s for over five years in the PNW without a single freeflow problem, and those are not considered good cold water regs. If you are careful when the air temperatures are very cold, you may not have any problems.

You should, however, have the regs serviced, if you are buying them used. Count that cost into the deal you are getting, to analyze if it's still a good one.

 

[keyshunter]

The AT 20 was usually sold with a US-4 first stage. It is a fine breathing reg. Although I don't know what a shop would charge for parts and labor, it is about a 5 minute job to upgrade the first stage to a DS-4 (cold water) first stage. The only difference in the second stage is the addition of a small heat exchanger at the hose attachment.

 

[Fishpie]

The US4 AT20 is a great balanced diaphragm reg with a balanced 2nd stage.
Due to its design it is already a good cold water reg.....diaphragm keeps water out of 1st stage and metal barrel in 2nd.
....the only reason it is marketed as a warm water reg is just that marketing.
The cold water specific regs add a 2nd diaphragm to the 1st stage and a slip on bit of brass to the 2nd.