cold water exposure suit debate

[undrwater]

Anecdote: this maybe explains why I feel much more energetic after dives with a significant thermocline.

 

[tbone1004]

listen to the Podcast that @Pod Diver Radio did with Pollock. It explains a lot. I don't think we can quantify how much of an issue it is without a bunch of lengthy studies that no one is going to fund, but the experiments done against a lot of accounts of DCS, and anecdotes of healthy dives in cold water deco diving align with their findings.

 

[BoltSnap]

t the experiments done against a lot of accounts of DCS, and anecdotes of healthy dives in cold water deco diving align with their findings.

What %%%? The percentage of divers getting bent is very low to begin with.

 

[BoltSnap]

I believe the issue is real, but probably only a significant concern for technical diving. I would GUESS that people doing recreational dives (i.e. single tank, with no deco stops) simply aren't in the water long enough nor deep enough to have any significant incidence of getting DCS as a result of a warm/cold dive.

With this account, people diving in the cold waters in New England with wetsuits, like I did for many many years, should have gotten bent long time ago if there were true to any extent. Dehydration is probably a much more of a factor here than what Tb is stipulating. I have heard more stories about people getting bent because and in the place of a overly tight knife strap than this issue with warm/cold suit diving.

This is the only thing I find that relates to Tbone's theory here:

 

[tbone1004]

not my theory, that belongs to the people who have PhD's and MD's in hyperbaric therapy doing the research.

 

[BoltSnap]

not my theory, that belongs to the people who have PhD's and MD's in hyperbaric therapy doing the research.

There are MANY theories and thoughts about many things in diving but that doesn't mean they are valid and have been accepted or used as a real reference until they have been scrutinized by peer review and accepted by all in the specialization. Just because somebody has a theory and is working on validating it, it doesn't make it a fact at all. If we go and live by all of the theories out there that haven't been proven or accept as true, we won't be able to leave our beds.

Even if it were true, the next question is; how much of a factor is it in the whole scheme of things in diving, especially recreational diving? Again, how many people were bent due to this issue out there? Where are the studies and facts related to this matter?

 

[tbone1004]

read the peer reviewed papers that were published, watch the presentations that were given at the Rebreather Forum 3.0 in 2012 and form your own conclusions based on that information. If you choose not to agree with it, that is fine. I agree with what they have presented and believe in it, but it is based on reading the papers on the studies that were conducted and watching the presentations, not on some random idea.

 

[stuartv]

With this account, people diving in the cold waters in New England with wetsuits, like I did for many many years, should have gotten bent long time ago if there were true to any extent.

Were you doing deco dives? Were you experiencing significant thermoclines that gave you warm water during the dive and colder water during deco?

If none of that was the case - i.e. you were doing single tank, recreational (no stop) dives, then no, what I said is that in that case, the increased risk of DCS from warm/cold diving wouldn't really be significant. As I said before, I suspect that No Stop dives (i.e. single tank, recreational depths, no deco) just aren't long and/or deep enough that a warm/cold dive is going to make much difference.

I think an example of where it would really make a difference is (as I said, for example), you do a decent deco dive in your drysuit in cold water. At some point after you've developed a real deco obligation, you rip a big hole your drysuit and it starts to really flood. You were warm, now you're ascending and doing your stops with a suit full of cold water. In that case, I think that you would have a significantly increased chance of DCS if you did your ascent with normal, modestly conservative GF (or equivalent settings for another algorithm).

Less extreme examples bring less of an increase in the chances of DCS.

 

[KevinNM]

Here an example of why cold during deco isn't ideal.

Diving Accident in Kaatiala, Finland on 26/6/2015

 

[Johanan]

The concept is understandable. How much influence does it have in real dives? Do any computers take this in consideration? Usually divers descend quite quickly and ascend at a slower rate. The main nitrogen uptake happens in deeper, cooler water and off-gasing in warmer temperatures. But it might be really interesting for a place like the Cueva del Agua cave in Spain where the temperature to some 9m is about 18C/65F and then, below a thermocline 29C/85F.