cold water

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Yes been there and seen that. One of the disadvantages of a high performance reg like the MK25 which puts out 300 scfm is that you will empty your tank from 3000 psi in about 120 seconds at the surface in a full-on free flow. Even faster at depth. Prevention is the key.

I think the spelling is Apeks and yes they seem to be the 'reg de jour' for cold water diving (<40 F).
 
pufferfish:
Yes been there and seen that. One of the disadvantages of a high performance reg like the MK25 which puts out 300 scfm is that you will empty your tank from 3000 psi in about 120 seconds at the surface in a full-on free flow. Even faster at depth. Prevention is the key.

I think the spelling is Apeks and yes they seem to be the 'reg de jour' for cold water diving (<40 F).

You're right about the spelling. One of those nasty habits I'm trying to break. Tendancy to freeflow was one of the key reasons I went with Apeks over the Scubapro.
 
cat:
Well, that's my reg, too, and so far, so good, down to 34F with 39F being a fairly common temp for the stuff I did last summer. Only had it about a year though, and only about - hmm - 40 or so dives in water below 50F? YMMV

Cat just curious do you have the 'antifreeze' on your first stage (one with heat sink fins on turret)? Also are you using high or low pressure tanks when diving the cold stuff? Of course I won't even ask you about the humidity of the air as we don't want to go there :wink:
 
cat:
Well, that's my reg, too, and so far, so good, down to 34F with 39F being a fairly common temp for the stuff I did last summer. Only had it about a year though, and only about - hmm - 40 or so dives in water below 50F? YMMV

Apeks or Scubapro? Either or, pop up to Cold Lake and try 'em out at depth. :D

So what is a 'JOAT' aquatic scientist doing in Edmonton?
 
pufferfish:
Warren just curious why the reg switch? Why don't you just dive the Apeks in all temps? By the way speaking of good gas management and free flow prevention have you noticed the new air certs on Aquarius web site? Now that is some dry air and takes one risk factor out of the equation for free flows.

I may very well do that. When I first bought my MK25 it was with a yoke connector and I switched to DIN valves when I bought my PST E7-120s, so I picked up an ATX-50 at the same time (wanted to get a sealed 1st stage as well). As a result, I have 2 regs now, which is fine. In the warmer waters I have often been working with students, I like the MK25 as the shop uses yoke tanks and plus I have a high performance reg which can handle the airflow I might need with students (not that the Apeks can't handle it too, but it is DIN and I actually prefer the MK25 as far as being able to handle high demand, all else being equal).

I've noticed when doing alternate air source skills with o/w students how for the most part the air is sucked back at a pretty good rate. I've counted as much as 3 or 4 breaths to one of mine.
 
regtech17:
I am trying to find information on what is considered "cold water" for a regulator. I have a scubapro mk25 s 600 and it's not a cold water reg. Can anyone give me information on what the minimum temperature it could be use at? I dive typically in waters 50 celsius and up.

Thanks

I have MK25/S600 for my back gas regs and they do just fine in cold water. Did hour-long dives on them in 32-35F water all winter. I did have my IP adjusted to 120-125 and inhalation effort increased to where i normally like it as compared to factory settings

After about 200 dives on this set, they freeflowed just once - on a day when it was -35C with windchill and i broke all the rules of getting in the water - i.e. kept popping up to the surface exposing my regs repeatedly. On that day, everything that could freeflowed including Apex DS1 on my stage bottle.

Vlada
 
glbirch:
Apeks or Scubapro? Either or, pop up to Cold Lake and try 'em out at depth. :D

So what is a 'JOAT' aquatic scientist doing in Edmonton?
Mine are the SPs (intervening posts about Apeks happened while I was typing). I was starting to wonder (shop here sells that reg a fair bit to cold water divers :D ) until vlada posted - hers have a lot more dives than mine do and under far more extreme circumstances (depth, air T, etc.). Mine have been to about 100' in 4C water, about 20' deeper in warmer stuff. Incidentally, was assisting with someone ELSE's FF that dive - they had ww Dacors, silly people :rolleyes:.
Maybe the secret is in the tuning/maintainence? If so, have to see how mine perform in cold now that they have had their first annual servicing.

glbirch - heh. A Cold Lake dive sounds like fun - any good open water right now? Dunno about depth though - I dive wet and at 100' there's not a lot of suit left - gets a tad chilly in deep 4C / 39Fwater. (I like the air to be warm when I get out, too - maybe when it's at least 10C out and sunny?) I wouldn't count on Cold Lake being a harder workout for the regs than they've already been through, though - was diving in the Thunder Bay end of Superior last year :D
Err the answer to your other question is - returning to my 'roots', looking for better work, pretending to write a thesis and plotting to either move or take some dive trips to the BC coast.
 
I dive a MK20/S600 set-up at about 0C water temp this time of year and have never had a free flow in the 150 or so dives I've used it. I usually keep the "inhalation effort control" set to minimum resistance. Doesn't seem to make a lot of difference either way.
 
I'll dive my MK20's down to about 50F unless I'm redundant and then I'll take them down to 40F. I won't go any lower than that, just too many free-flows.

In water colder than that I only use DS4's or TX100's, although I hear good things about some other brands, too.

A couple of years ago SP came out with a cold water rebuild kit that I tried. The only problem was that I took the regs to Hawaii and blew one of them out - the warmth caused the softer seats and rings to deform and I blew them out.
 
reefraff:
I'll dive my MK20's down to about 50F unless I'm redundant and then I'll take them down to 40F. I won't go any lower than that, just too many free-flows.

I agree with you there. The AF kit is still not the ultimate answer to the problem.


A couple of years ago SP came out with a cold water rebuild kit that I tried. The only problem was that I took the regs to Hawaii and blew one of them out - the warmth caused the softer seats and rings to deform and I blew them out.

Not sure what kit this would be. The AF kit came out last June. SP has changed O-ring materials from time to time over the years and has changed seat designs, but none of them would have been affected by warmer water (short of diving in a boiling hot spring or hydrothermal vent).

I suspect the problem was coincidental with the trip. More Murphy's law than softer seats or o-rings.
 
https://www.shearwater.com/products/swift/

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