Cold Water Free Flows

[Herb-alaska]

that is some cold diving. I have had many dives where i did not want to come up because the water was warmer than the air but crude that sounds like cold water

.... really?

Where I live freezing regs happen a fair amount in the winter. Water temps get down to just about freezing so any momentary freeflow, which can easily happen, for example, during an entry, will cause the reg to freeze. Normally turning off the tank for 5 minutes will allow it to thaw and the dive can be continued. Obviously under water you can't do that without redundant gear so for that reason you see a lot of divers in our local area using twins and Y/H valves and dual regs.

I really don't see many freezing under water, tbh, but we all use environmentally sealed regs. Also, normally when they go it doesn't immediately cause violent free flow--sometimes vigorous bubbling but usually not the violent types of free flows you would see from, for example, a dislodged HP seat. I really wouldn't expect someone to panic from it.

The most free flows I ever saw on a dive was in the Czech republic when we were diving under the ice. The problem wasn't the water temperature, it was the air temperature. -15C with a wind. Shortly after entry with three divers we had 3 inflator hoses and 2 out of 3 drysuit hoses frozen. All the regulators were still working. We hung around the entrance for a good 5 minutes to let the water, which was only +2, *warm* up our gear

During that dive one of the divers had a dry suit develop a leak due to a small rip that formed from the cold (a DUI with that light trilam that you shouldn't use in cold water) and two of us had freeflows upon surfacing. In my case I bumped my reg while climbing out of the water and by the time I got to it, the 1st stage and hand wheel from the k-valve were covered in ice and shortly there after it was a block of ice. The set stood all afternoon my our host's garage before it was thawed out enough to close it. I should have taken pictures but I didn't think about it.

R..

 

[Timmyjoe]

Well that was a bunch of worry for nothing. When I found out a few weeks ago that I would be doing my AOW Deep Dive in a local quarry, where, because of our severe winter, the water temp was supposed to be in the lower 40ºF range, I got pretty concerned that my Legend LX might freeze its first stage and free flow on me at depth. Well, we did the dive today, and at 71 feet, the temp only went down to 62ºF, and everything worked just great.

Thanks again for everyone's input.

Best,
-Tim

 

[spectrum]

62F at 71' in a quarry near Chicago on June 1? Is a nuclear power plant using that pit for cooling?

 

[Timmyjoe]

Must have been. The guys I was diving with weren't really happy with the water temp at 71 feet, but I thought it felt really nice.

Diving last weekend at Haigh Quarry, where we were at 50 feet and it was 44.5ºF, that felt really cold to me. My cheeks were not liking that at all. But the temps today were fun.

Best,
-Tim

 

[bada3003]

It can happen if there is water on the inside of the 1st stage or in the internals of the 2nd stage valve. Both of which can happen from over zealous rinsing after the dive when the reg is not pressurized.

There does NOT need to be water in the 1st stage for freezing induced free flow to occur. This is called adiabatic cooling. I wish the cert agencies would teach these (and other) basic safety facts during OW training.

---------- Post added June 5th, 2014 at 08:16 PM ----------

62F at 71' in a quarry near Chicago on June 1? Is a nuclear power plant using that pit for cooling?

Probably a typo. There aren't that many quarries with depth in the 70+ feet range in our neck of the woods. At Haigh a couple of weeks ago, it was in the low 40s around 50'. At Gilboa this past weekend, it was a nice refreshing 38F around 110-120'. The nuclear folks must be keeping them as redundant backup.

 

[Timmyjoe]

Probably a typo. There aren't that many quarries with depth in the 70+ feet range in our neck of the woods. At Haigh a couple of weeks ago, it was in the low 40s around 50'. At Gilboa this past weekend, it was a nice refreshing 38F around 110-120'. The nuclear folks must be keeping them as redundant backup.

Not a typo. It was 62ºF at 71 feet at Pearl Lake (which is a quarry, and the hole at Pearl was 71 feet the day we dove it, it can range from 73+ to 68- feet, depending on the water level of the lake). I dove Haigh the week before, and Haigh was MUCH colder than Pearl. Have no idea why, it just was. No typo.

Best,
-Tim

 

[bada3003]

Thanks for the clarification. Haven't visited Pearl Lake yet but may be worth making a trip north one of these days. Both Haigh and Gilboa have well-defined thermoclines, unlike, it would appear, Pearl Lake.

Not a typo. It was 62ºF at 71 feet at Pearl Lake (which is a quarry, and the hole at Pearl was 71 feet the day we dove it, it can range from 73+ to 68- feet, depending on the water level of the lake). I dove Haigh the week before, and Haigh was MUCH colder than Pearl. Have no idea why, it just was. No typo.

Best,
-Tim