Cold water diving

[off the grid]

Went diving this week in Montana and our computers both said the water temperature was 30 degrees at about 60 feet. I understand that increased pressure will lower the freezing point but didn't think it would be that much at that depth. Just wondering what the coldest water temps anyone has experienced in fresh water?

 

[captndale]

Have you considered the possibility that your thermometers might be slightly in error?

 

[MurkyRockDiver]

I have seen 28F in Salt water but not fresh, what was you altitude?

 

[RJP]

If you don't have to cut a HOLE in the top to get in...

...THE WATER ISN'T COLD!

 

[Rick Inman]

Yeah, I don't think it's been cold enough for long enough, even in the mountains of Montana, to hit 30 yet. What did your buddy's computer say?

 

[richerso]

Wooo!
Already, I love this thread! I am sending it to a couple of friends! RJP! I am with you! I am going ice diving at Okoboji, Iowa in February!

OffTheGrid,
I don't have a real good answer for you offhand. Thermodynamics says:
1) There is a modest a relationship between increasing pressure and increasing freezing point.
2) There a a moderately strong relationship between increasing molality (one measure of salt / impurity content) and decreasing freezing point.

As has been mentioned, your temp gauges could be slightly off.

Also, question to you. Does your nickname imply that you are off the national power grid?

 

[Gary D.]

If you don't have to cut a HOLE in the top to get in...

...THE WATER ISN'T COLD!

Join the Navy. THE WATER IS NEVER COLD!

We came very close to an Ice Dive last night.

Gary D.

 

[off the grid]

We were diving at about 4000 feet altitude. Both computers said 30. I know phase diagrams for fresh water show an initial decrease in freezing point with increased pressure but not that much. Just odd both computers would be off. I'll have to check again this weekend. Gary, were you doing an SAR dive or just recreational?

 

[Tomeck]

Ice diving is beautiful !

In Switzerland, I dive under ice in 6085 feet altitude :

 

[KOMPRESSOR]

Those are some cool(!) pics Tomeck! What kind of fish is it I see in one??!

Here are some from me: Ice, Ice, Baby!


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