my first very cold water dive

I did my first cold water dive yesterday, and I have to say I was surprisingly comfortable ( I expected to be quite cold) with my 7mm full and 7mm core, water was a tropical 36 F, we stayed in the water for 20 minutes but only dove for a total of 4 minutes, my buddies reg froze up and free flowed, so we shut off his air and just floated and talked. My mk17/g250v worked well, his mares rebel12 on the other hand didnt work well in 36 F water, but worked ok in 46F water.

What part is it that freezes, the first or the second stage, or both?

Cool!

I don't know if the rebel is cold water rated...but with any reg, if you are diving water that cool, do not breath on the reg until you are under water, and stop breathing before your face breaks the surface when coming up. The moisture in your breath is what freezes the reg. BTW I was ice certified in a 7 mil and core warmer...but my drysuit sure makes it more comfortable....Who needs the tropics to dive?

Congrats. I just did my first as well a few weeks ago. 28 degrees F for just over 15 minutes in a two piece 7mm. Only problems I had was that my power inflater froze up before I jumped in.

Siantis:

Congrats. I just did my first as well a few weeks ago. 28 degrees F for just over 15 minutes in a two piece 7mm. Only problems I had was that my power inflater froze up before I jumped in.

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you are brave guys after diving in 36F water in a dry suit I said myself there is no way I would do that in a wet suit

Congratulations, Tim. 36 is serious cold.

Do I read you right that you had two 7-mil layers?

I got in a local lake this morning to check out conditions. At least it was 41, not 36. And I was drysuited, so my buddy and I had a nice 45-minute swim.

I'll find some links to recent "freeze-up" threads and post them. Usually the first stage starts it, the second breaks open under the pressure. But there are differing views on that.

-Bryan

What I've posted somewhere else this year is:

When the air is cold, breathing off the reg or using the BC inflator (on the surface) can cool the first stage to the point where it will freeze up once in the water. This is in my experience the most usual cause.

So your gear assembly and testing routine needs to be different in cold weather. Don't take more than a sip of air on the second stages, if you must. Keep the first stage out of the wind--put a heavy sock or a watch cap over it if it's going to sit out on the tank for a spell before you get in. Inflate your BC orally to start. Once you're under the surface the water will transfer enough heat to the first stage (even very cold water has heat) to keep it from freezing, as long as you're not breathing hard or leaning on a BC or drysuit inflate button. Short bursts with long pauses between them is ideal. I've also seen freeze-ups start underwater during reg retrieval drills, because of overuse of the purge valve.

Turning off the air for a few minutes is usually enough to allow the first stage to thaw underwater. Of course, breathing hard off your buddy's tank now puts that reg in danger of freeze-up, so sometimes ascending while sipping from the free-flow is the way to go. That can be a good skill to know.

http://www.scubaboard.com/forums/te...ies/47081-1st-stage-freeze-up-prevention.html

http://www.scubaboard.com/forums/basic-scuba-discussions/41978-tis-season-freeze-flows.html

http://www.scubaboard.com/forums/regulators/18344-regulator-freeze.html

http://www.scubaboard.com/forums/regulators/4626-regulator-freeze-up.html

Okay, that's more than anyone will ever read. Note that some of these are very old threads and replying to old threads is considered gauche.

-Bryan

Congrats! My 1st cold water dive is next weekend! Yikes! But to me 58F is freezing ;-) You're making me feel much better ;-)

Bryan St.Germain:

Congratulations, Tim. 36 is serious cold.

Do I read you right that you had two 7-mil layers?

I got in a local lake this morning to check out conditions. At least it was 41, not 36. And I was drysuited, so my buddy and I had a nice 45-minute swim.

I'll find some links to recent "freeze-up" threads and post them. Usually the first stage starts it, the second breaks open under the pressure. But there are differing views on that.

-Bryan

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yes I had a henderson hyperstrech 7mm and a bare 7mm core warmer (shorty)

Yeah, I won't dive wet below 70 degrees F.

Recently I dove dry in my local lake, it was 50 degrees. I thought that was chilly.

After the dive, I took a dump in my dry suit just to have a warm place to sit down.