cold water vs. warm water

[elan]

I agree that the conclusion, presented by the OP, is unassailable. To wit: "warm- and pool-water practice "may" [sic] not prepare a diver for the rigours of cold water diving."

I would replace "may" with "will" oh what a big difference do you fill when you come to a pool or go diving in 4 mill wetsuit in a 75F lake or ocean with single AL80 after diving double tanks in dry suit with warm undies in 41F water.

Buoyancy control is much easier. You practically do not inflate the BC , almost everything can be compensated with the lungs no dry suit venting ... no thick gloves what a difference.

 

[Van Isle]

*NB I can't find my sources right now...*

As an aside, I think it's also important to note that as far as in-water experiences go, hypothermia does not, as a general pathological rule, kill divers (or boat accident survivors, etc.)

Hypothermia causes loss of function that usually leads to drowning, something a diver can resist by having sufficient buoyancy on the surface. The root "cause" of death might be hypothermia - or being lost, or surfacing low on air, or being too dumb to wear proper exposure protection - but the pathological cause of death in most in water-deaths often attributed to "hypothermia" is drowning. As such one should recognize that the times listed for in-water survival earlier are assuming that you don't lose motor ability and drown first.

 

[Ashmai]

I did my open water dives for my cert in cold water. First experience into the ocean. It seemed normal at the time, but man... after a trip to Belize, the differences in diving were sure clear to me

 

[shoredivr]

diving double tanks in dry suit with warm undies in 41F water.

That describes three quarters of my total dive experiences.

 

[tregrrr]

As a Wet[sic] Coast, Canadian, diver, I learned in conditions where the warmest open water I had ever seen was 55F (at the end of a heatwave.) When I went down to the Caribbean and found out the water was 77F (2 degrees warmer than the school board kept the swimming pool we rented), I wore board shorts for the next 6 months before finally putting on what used to be my pool wetsuit.

After 6 months of wearing the 2mm shorty and with water temperature getting up to 83F and receding back to 80, one day I found myself sooo cold after the 3rd 50minute dive of the day that I, a Canadian, finally broke down and put on a full length 7mm suit out of the rental locker.... and proceeded to have a spectacular night dive.

My point is that our perspectives, metabolism and tolerance shift radically according to what we accustom our bodies to. This lends credence to the assertions made previously. New, inexperienced, warm water accustomed divers NEED to be especially cognizant of reality when their reality changes to include diving in cold water.

Since this thread seems to be about throwing hydrocarbons onto fires... I will also throw a reference to DCBC's deep air discussion into the mix. Acclimatization and familiarization are at the heart of allaying panic (IMHO). I KNOW from personal experience that after coming back from the warm waters and getting back into my drysuit that by not doing cold, deep, dark, bad viz for a year, I am not as capable as I once was wrt cold tolerance, narcosis tolerance, and 'gut instinct' situational and positional awareness. These are all aspects of our less than ideal conditions that you take for granted, and do not realize how attuned you really are when you build said skills set up over a period of months or years.

We all agree that the amount of training recieved in a warm clime is woefully inadequate for diving cold right?? So then why can't we suggest that there possibly is some way the certification agencies differentiate between "warm" and "temperate" in the issuance of diving credentials?? I remember some of my guests in the warm waters coming to me with C-cards older than I am. The one thing I noticed different was many indicated TEMPERATURE of their certification dives. I never asked, due to lack of time and being already over tasked during check-in, but I assume that by recording that salient information, in the old days, this information did make a difference.

What if there was a separate classification for diving in areas where cold is normal??

To use PADI's levels for example:

scuba diver
open water
open water (cold)
advanced
advanced (cold)

If you learn in cold water, great, you get your OW(c) when you pass your OW course. If you get certified in warm water or take a referral, you recieve your OW, which is only valid in water warmer than say 10 farenheit degrees below of your certification temperature.

In my thought it would be much like getting an endorsement on your driver's permit.
I propose that it DEFINITIVELY not be a specialty since specialty certifications are like the highway warning signs before a corner: only the cautious drivers pay heed to those 'recommended speeds' and it typically isn't the cautious diver we are especially concerned about is it??

This hearkens back to the adage "There are bold divers and there are old divers. There are no old bold divers"

This would force warm trained divers to take a locally applicable skills course and meet a level of competence in local conditions before being able to rent gear or get fills locally, to dive alone, but would allow escorted dives under instructor supervision until the standard is met. I (in my very sleep deprived current state) would envision this to be much like a Scuba Diver cert; the concept is similar since they teach just enough 'skills' so that a scuba diver can dive with supervision. Similarly, in the tropics they teach OW divers just enough skills to dive in cold water under direct supervision...

[/UnfilteredThoughts]

Please excuse rambling and mental drivvel; insomnia sucks as mental process stimulant. it also inhibits the ability to correctly process dates and times such as those associated with when posts were made

This post kind of hit home after seeing some serious floundering the likes of which I typically associate with warm divers learning cold buoyancy. Please accept apologies for waking a dead horse for another potential round of beatings

 

[Mike Boswell]

For those cold water divers, I'd like to highlight some of the points raised in Alert Diver Magazine, Fall 2009, Dive Slate:

"In the last four years, DAN [Divers' Alert Network] has recorded 68 fatalities in the inland waters of the United States and Canada an just 20 fatalities [OP note: here I assume `in the same diving constituency'] abroad. Contributing factors in inland fatalities often involve cold water, poor visibility and unforeseen objects."

"Their [Eric Douglas and Petar DeNobel] conclusion: Practicing emergency procedures in a swimming pool or in comfortable Caribbean waters may not be sufficient training for problems that arise in less favorable conditions."

Even when I make a conscious effort to relax and conserve air, my SAC rates in cold water (55F) are MUCH higher than those in warm (75F) water. However you explain that, to me it would seem to be an indication of increased work and stress.

 

[Crush]

As a Wet[sic] Coast, Canadian, diver, I learned in conditions where the warmest open water I had ever seen was 55F (at the end of a heatwave.) When I went down to the Caribbean and found out the water was 77F (2 degrees warmer than the school board kept the swimming pool we rented), I wore board shorts for the next 6 months before finally putting on what used to be my pool wetsuit.

After 6 months of wearing the 2mm shorty and with water temperature getting up to 83F and receding back to 80, one day I found myself sooo cold after the 3rd 50minute dive of the day that I, a Canadian, finally broke down and put on a full length 7mm suit out of the rental locker.... and proceeded to have a spectacular night dive.

My point is that our perspectives, metabolism and tolerance shift radically according to what we accustom our bodies to.

I had a similar experience living in Italy. After returning home I couldn't believe how cold I was all the time.

So then why can't we suggest that there possibly is some way the certification agencies differentiate between "warm" and "temperate" in the issuance of diving credentials??

...

To use PADI's levels for example:

scuba diver
open water
open water (cold)
advanced
advanced (cold)

I am personally not in favour of having certifications for everything under the sun. For what it is worth I advocate the approach that in some cases you can try something different without having the card for it (e.g., learning to dive a drysuit), but in such cases be extra cautious and keep the profile simple (NOTE: a few examples of where this approach would be foolhardy are cave-diving and wreck penetration). I believe that warm water divers should be aware that cold water is very different and while some of their warm-water skills transfer to cold water, some of their warm-water-acquired preparation will be lacking or totally absent. At very least, gear-rental shops in Vancouver should be careful to take a very clear credit card imprint from divers with southern drawls in case their equipment does not come back.

 

[Crush]

Even when I make a conscious effort to relax and conserve air, my SAC rates in cold water (55F) are MUCH higher than those in warm (75F) water. However you explain that, to me it would seem to be an indication of increased work and stress.

Having a drysuit seal on my neck with a hood and mask in place elevates my breathing rate.

Last year I did my warmest dive ever - a West Palm Beach boat dive in April. I wore my 7mm top with no farmer john and no hood. Early on I told the DM that I was a hoover, and that I was happy to call my dive and surface on my own (he declined this, indicating that the group of eight would stay together). As it happens I had a good 1200+psi left when others had sucked their tanks back to 500 (the dives were pretty shallow).

Warm-water diving is (by comparison) almost effortless.

 

[Kingpatzer]

Appropriate thermal protection removes most of the stress. There is likely to be a bit more load on the diver due to the increased mass (most important out of the water) and increased bulk and shifts in trim can become issues.

For even moderately experienced divers, what you say is undoubtedly true. However, I'd suggest that for a new diver, the shock of entering 55* water in a 7mm is a significant stress event compared to that same diver entering 80* water. Moreover, those first 5 minutes in the water trying to adjust to the temperature, get over the shock of the initial cold, and allowing the wet suit to do it's thing is a significant amount of time in which things can go very wrong.

 

[TSandM]

Appropriate thermal protection removes most of the stress

However, I'd suggest that for a new diver, the shock of entering 55* water in a 7mm is a significant stress event compared to that same diver entering 80* water.

I agree with both of these statements, and draw the unavoidable conclusion that a 7mm suit is not appropriate thermal protection for 55 degree water!