(Extreme) Cold Weather Diving

[Littlerayray]

I was factoring in the fact that you already breathed off the tank

 

[underH2Oman]

I would say dive from a heated ice fishing hut but we both know that that takes ice which we do not have much of this season.

Some of my fondest memories of cold weather diving is watching people get out of a wetsuit standing on a picnic table covered with snow. Ohh how I love Canadian winter.

Now off to pack for Honduras. It is winter there as well!

 

[Littlerayray]

Yeah yeah keep bragging

 

[TMHeimer]

minus 21C--I assume that may be with wind chill? Man, you don't want to f*&^ around with those temps. with dive stuff, I would at least imagine. We're in N.S. the last 10 years and in mid winter I gear up inside and do a dive (wet) from the house. I'm paranoid about even leaving my gear outside for any length of time while disrobing inside, and this is Nova Scotia right on the shore where winter temps. are milder. You don't want to mess with real cold-- like my 25 years in Northern Manitoba of 3 months at least of avg. daytime air temp. of -30C (-22F)--many days at -40(C-F-same at -40) or below -- NOT with wind chill--at times minus 80 with wind chill. Cold is nothing to disguard, it will freeze anything.

 

[gcarter]

minus 21C--I assume that may be with wind chill? Man, you don't want to f*&^ around with those temps. with dive stuff, I would at least imagine. We're in N.S. the last 10 years and in mid winter I gear up inside and do a dive (wet) from the house. I'm paranoid about even leaving my gear outside for any length of time while disrobing inside, and this is Nova Scotia right on the shore where winter temps. are milder. You don't want to mess with real cold-- like my 25 years of 3 months at least of avg. daytime air temp. of -30C (-22F)--many days at -40(C-F-same at -40) or below -- NOT with wind chill--at times minus 80 with wind chill. Cold is nothing to disguard, it will freeze anything.

That would be a real temperature, not wind chill. Raw temp in Ottawa today was ~ -25C

 

[2airishuman]

Minneapolis is north of Toronto, and colder....

To your original question, your SPG should work fine in freezing temperatures. That it did not indicates that there's water somewhere in the high pressure circuit. Could be the tank value, Bordon tube (inside the SPG), or anywhere in between.

I don't know much of anything about diving but I do know that if I became convinced that an SPG had water in the Bordon tube, I would apply high vacuum to it for half an hour. Either put the whole instrument in a bell or just the pressure fitting.

 

[TMHeimer]

my

That would be a real temperature, not wind chill. Raw temp in Ottawa today was ~ -25C

A very balmy day compared to Thompson, Manitoba winters, but still--plenty cold to not really mess with anything outside that you don't want to freeze.
I have dived in as cold as 33F (+1) water--not very LONG diving wet mind you, but I never had a reg problem. Of course the reg and everything else was inside to start with. In moving from my native NYC to the Subarctic, I soon developed a healthy respect for the deep freeze. Come September (just before the early Oct. snow starts), I made sure everything that was outside was in such a position that it could be moved if need me in January--so it wasn't frozen solid 'til May. That is why for no real reason, I don't like leaving the reg, wetsuit, or anything outside after a dive longer than it takes to get dressed--and it may be only 0C here in NS.
Now, being here in Mississippi for 2 months, I fear the opposite. Don't leave stuff--especially tanks in a closed in car in the sun.

 

[gcarter]

This is where I grew up.

 

[TMHeimer]

g, Wow. Our schools (where I taught in Thompson) were only closed one day from the beginning of the town (1956) to when we left in 2005, and that was due to 6 feet of snow, not cold. On the coldest days of -40C or lower, that was just considered normal, though the usual radio warnings of "exposed skin freezes in less than a minute", etc. But the temps. on the letter from your Lab City school principal are really pretty bizarre. They MUST mean with wind chill. Minus 68 or 83 C would be freakish for even extreme Northern Nunavut. -88 in Yukon apparently holds the record all time recorded low in Canada for sure, maybe all of N.A. The coldest temp. I ever saw in Thompson was -48C (-53F), though recently I believe it did pass -50C.

 

[gcarter]

g, Wow. Our schools (where I taught in Thompson) were only closed one day from the beginning of the town (1956) to when we left in 2005, and that was due to 6 feet of snow, not cold. On the coldest days of -40C or lower, that was just considered normal, though the usual radio warnings of "exposed skin freezes in less than a minute", etc. But the temps. on the letter from your Lab City school principal are really pretty bizarre. They MUST mean with wind chill. Minus 68 or 83 C would be freakish for even extreme Northern Nunavut. -88 in Yukon apparently holds the record all time recorded low in Canada for sure, maybe all of N.A. The coldest temp. I ever saw in Thompson was -48C (-53F), though recently I believe it did pass -50C.

Of course, at the start it says chill factor included - and to be fair, I believe the old method for calculating chill factor made it sound worse.

How Is Wind Chill Calculated?

Has the formula always been the same?
The above formula is actually a fairly new development that the National Weather Service introduced in late 2001. During the year 2000, the National Weather Service and its Canadian counterpart had independently started looking for ways to improve the wind chill formula, partially because they had a sneaking suspicion the old formula overstated just how cold it was. This overstatement may sound innocuous, but the weather services worried that it would lull citizens into a false sense of security if it led people to believe they could withstand colder temperatures than they realistically could.

Since the collaborating weather services knew that the old wind chill formula was broken—"feels like -50" actually felt much warmer than standing around on a windless 50-below day—they recruited a group of volunteers to walk on treadmills in a refrigerated wind tunnel. Using sensors on the subjects' skin, scientists calculated a more accurate formula.