Rescue divers' equipment freezes during body retrieval

[dittrimd]

Eazy beeswax, while am sure Gary appreciates you defending him it seems you got the wrong idea from my post. I am not an expert at articulating myself very well in text so please excuse me if my original post did not come through clearly.

First off I was not disagreeing with Gary in any way nor was I trying to discredit him. I was only stating my experience with the AGA and my thoughts on why the mask might offer better protection against free flows. I agree that AGA masks like any regulator are susceptible to free flow and that operator error and improper maintenance are certainly contributing factors. I was just offering up my experience with the AGA mask. Our masks do not have a gill on them so we must don the mask and start breathing on them prior to getting in the water. Here in Connecticut we do not get the weather they do out in the Upper Midwest but my last dive which was an actual emergency response was a night ice dive with and ambient temp of 2 deg F so we do get pretty cold. I had to put my mask on and slide backwards into the open ice. I was breathing on my mask for about 30 seconds. I did about 15 minutes in the hole and surfaced. I went back down for one more pattern and then completed my dive.

As for the heat sink comment I simply meant that the mask having more contact with my face and having warm air in the mask might just help keep the entire mask assembly/regulator and the air around the inlet valve warmer thus preventing the moisture from freezing. This is only a thought and not something I have proved scientifically. I was more posing a question rather than stating a fact. Again sorry if I do not articulate myself very well in print, I hope I did a better job this time.

Mark

 

[beezwax]

Apologies if I sounded aggravated, I am not invested in Gary's honor in any way. But if you read enough PSD threads here you have to concede that he knows what he is talking about. And I understand that you were simply postulating, although you should really stop using the term "heat sink" because it's precisely opposite of what you're trying to describe.

And as to the idea that the warmer air inside the enclosed volume of the ffm might somehow be responsible for preventing a freeze up....I can't imagine how that could be so. The air that is taken in upon inhalation will be freezing cold regardless of whether it comes in through the reg (from the tank) or in through the gill (from outside). The reason why AGAs with gills or "ambient breathing valves" experience far fewer freeze-ups/free-flows under extremely cold conditions is exactly because this freezing cold air does not cross through the reg. Only the warmer exhalations do. Obviously if you exhale warm moist air through the reg, and then inhale freezing cold air through the reg, that is the moment when a water droplet is most likely to freeze and cause the valve to stick open. The gill breaks that circuit.

But I too am only hypothesizing.

 

[beezwax]

Mark let me also say welcome to ScubaBoard, this is a great resource, and if/when people get their hackles up just take it all in stride. Everyone, myself included, loves the sound of their own voice.

 

[bane51031]

All I can say is this happened very close to home for me, as a new member of our dive team and this happening about 45 miles from home , however that being said our team underwent SIR and ice diving training last weekend, very cold here with several inches of snow, no problems with equipment freezing and our instructor was adament on not breathing until reg. underwater to prevent this problem and again no problems encountered. We do not have the full face mask (yet) hopefully soon and we had to borrow drysuits for the training, hopefully getting those soon too as well.
A tragedy for the victims family but, if any good comes out of it it shows our local community the need for our services and the need for proper equipment.