What if DIR Evolved Elsewhere... (take two)

[do it easy]

I will do that for Ice diving now. Never hook it up is my new sop.

How cold are the ice dives up in Canadia? Last year, we had below freezing air temps, but the water was 38f-43f/3c-6c.

I think rivers with flowing water can get colder, but I've only been ice diving in quarries.

 

[JeffG]

How cold are the ice dives up in Canadia? Last year, we had below freezing air temps, but the water was 38f-43f/3c-6c.

I think rivers with flowing water can get colder, but I've only been ice diving in quarries.

The water temps we were having were ~33f. A touch warmer at depth (but not much. maybe 35)

 

[Mike Edmonston]

The water temps we were having were ~33f. A touch warmer at depth (but not much. maybe 35)

Yeah, I think we hit 34 at the coldest.

 

[MXGratefulDiver]

Brrrrr ... coldest it gets here is low 40's and that's about as cold as I think I want to dive.

What's your typical dive time at those temperatures?

... Bob (Grateful Diver)

 

[do it easy]

When it gets that cold, every few degrees is a world of difference.

We were doing two dives, 45-60 minute each.

 

[Gilldiver]

By the time you get to the hose to unhook the QD the inflater is covered in a ball of ice. Besides the fact that unhooking one of those things with 2 or 3 sets of insulation gloves and a nice sloppy blue glove on isn't exactly quick. Me? Well, if I still was insane enough (read had the time anymore (17month old)) to dive in freezing temperatures I would start the dive with it unhooked. That power inflater is just tooooo finicky and consequences of failure much to high (scared ***less, hospital or dead) when it is dirt simple to orally inflate.

Then I guess you are also worried about having the same problem with your dry suit inflator. They are both essentially the same thing.

The coldest I have ever been in is the Gulf of Maine in February with an air temp of 24F and water temp of 29 or 30F. But this is salt water and fresh water can be different. But, I will grant you that thick gloves are a problem at the best of times. So, have you ever thought to put a collar around the quick disconnect on both the BC and dry suit QC's? It is not a new idea and has been used at McMurdo Sound, Antarctica for years and they have way more dives in ice conditions then any here will ever have.

Check out this site for some relevant info, it is a bit dated but still relevant.
Diving under Antarctic Ice
Specifically this page:
Diving Under Antarctic Ice
There you will find this, "The drysuit inflator valves on the drysuit air inflator line are specially modified at McMurdo to put a larger knurled brass collar on the valve end so that clumsy, cold fingers can easily pull that valve on and off."

I also spoke with one of the Diving Safety Officers that has worked down in the area and he has never seen or heard about an iceing of a BC inflator like you describe. Has it happened to you or have you seen it? Or, is this one of those I heard of a guy who…

 

[Mike Edmonston]

Brrrrr ... coldest it gets here is low 40's and that's about as cold as I think I want to dive.

What's your typical dive time at those temperatures?

... Bob (Grateful Diver)

35 to 40 minutes

 

[Gilldiver]

A bit off topic, but have you ever seen a diver with a neoprene or crushed neoprene dry suit a few minutes after getting out of the water at bellow freezing temps?

At Cape Ann I saw two get out and had their suits freeze just about solid. They were stiff and we could not get the zippers open. Eventually they got into the car to thaw out so they could get their new DUI CF's off. Got the car a bit wet to say the least.

 

[JeffG]

Brrrrr ... coldest it gets here is low 40's and that's about as cold as I think I want to dive.

What's your typical dive time at those temperatures?

... Bob (Grateful Diver)

We would keep the times down to around 30mins. People do dumb stuff when they are frozen. So we would rather do shorter multiple dives instead of one long dive.

 

[Thalassamania]

I also spoke with one of the Diving Safety Officers that has worked down in the area and he has never seen or heard about an iceing of a BC inflator like you describe. Has it happened to you or have you seen it? Or, is this one of those I heard of a guy who…

I just read through Peter's wonderful story about diving in the Antarctic, thaks for the link. I am left with a real concern, and you hit the nail on the head: "never seen or heard about an iceing of a BC inflator like you describe." I have to concur, but I can't imagine that everyone reporting such an occurrence is making it up. In fact it appears that I've been remiss, or at least a dash negligent, there was an AAUS Workshop on Polar Diving (Rubicon Link) back in 1992 (I did not attend, I was on a cruise), the freezing problems were discussed, in passing. Clearly it was not a big enough issue to have everyone concerned and talking about it, most of the talk was with respect to the possible required of using a BC under the ice:

J. Bozanic:

One thing that should be noted is that adding a BC as a mandatory piece of equipment increases the chances for failure in another piece of equipment. From my notes, there were three failures of inflation valves on BCs in the 1989-90 season and two additional ones on the dry suit inflation valves themselves. The need for a BC in under-ice situations should be balanced against the increased possibility of blowup failure in the BC itself.

S. Bosch:

I agree with everything you said. The real problem with diving in any kind of cold water is that you already have too much equipment, so I have to see a really concrete reason for adding another piece. In my experience down there, I only know of one person who has had a massive flooding of his suit, and there he is right there. (pointing to a workshop attendee). Every season I hear of several people whose buoyancy had failed or experienced a free-flow of air into their suit or BC.

D. Long:

As a rule, all the inflator devices I have seen freeze when you try to activate them. As long as you do not touch them, they do not inflate. If you get pinned underneath the ice, all modern BCs - have a venting valve in their backside. You can vent in any direction. So an inflated BC is not that big an issue when you get down to it. Besides, you should never use it, unless you need it. If you need it, then you have another problem altogether.

A.P. Valves in Britain makes a variety of BCs, some of which have a high pressure bottle, as an independent inflation source. There is no low pressure mechanism on some of these systems at all. You inflate the BC with a high pressure valve, and the chance of a freeze up is very unlikely. So there are alternatives and you should ever say lightly "this is something that you have to do." It is also something that we need to work out the procedures for, better than we have done so far.

D. Long:

The purpose of the rapid exhaust valve in the BC is to get the air out as fast as you pump it in. That is no factor with freezing; just get rid of all the air if the inflator freezes open. In the case of dry suit valves, freeze-ups often occur when people do not check the valve before going into the water or if there is water in it. The first time they hit the inflator it freezes. Hitting it again once or twice will usually break the small crystal. That is why people ought to hit that inflator a couple of times before they start down. If a freeze-up is going to happen, our limited experience tells us that is when it will happen.

BTW: This is another example of the peer review and consensus reaching approach we were discussing earlier.