Semi-dry or thick wet?

[Tigerman]

Wet = Cold
Dry = Not Cold

PS - no reason to "drop a couple grand" on a dry suit; several nice ones avail for far less; esp used

Indeed.. You get perfectly good, brand new drysuits for 1000-1200 USD. Problem is that people might think that its not good unless it says DUI on it..

 

[mania]

Indeed.. You get perfectly good, brand new drysuits for 1000-1200 USD. Problem is that people might think that its not good unless it says DUI on it..

Geee, mine says Hunter/Gates


I must be out of style.

OK, it was very much in-style in Europe.

 

[RJP]

I haven't been diving long, so my dives are fairly short (SAC only really allows me 30min or so), but I'm yet to get cold in my 1piece 7mm in ~50F.

You've clearly also not been diving long enough to recognize that "I've yet to die of hypothermia" is not the same as "I've yet to get cold."

:cool2:

But seriously, there is a very real physiologic difference between "I didn't get cold" and "the cold didn't bother me." Cold water (50F water is cold) exerts specific negative impacts on your body...whether you "feel cold" from a comfort standpoint or not. If you and another person of equal size and wearing similar thermal protection are put into 50deg water for 1/2hr, even though you might not "feel cold" your core body temp will drop at the same rate and to the same temp as the other person, who may be shivering violently. Whether it bothers you less than the other guy does not exempt you from the same laws of thermodynamics; conduction cooling is a function of water temp, body surface area, and time.

Because of that, the fact that cold water temperature "doesn't bother you" as much as other people is actually a bad thing. While others' bodies are telling them "it's time to end the dive" long before they get anwhere near having a problem, you're body is saying "c'mon in, the water's fine!" So even though you may not "feel the cold" even a mild drop in core body temp diminishes physical and mental abilities, thus increasing the risk of you having an accident AND/OR decreasing your ability to effectively respond to an accident.

Additionally, while the effects of cold water on your body are related to the time of exposure ,that relationship is non-linear, meaning that you might be "fine" at 20min, "fine" at 30min, even "fine" at 39min, and suddenly "shivering violently" at 40min. Worse still, this time aspect typically varies from one dive to the next based on other factors - mood, hydration, stress, activity level, task loading; even things like viz, surge, currents, etc. Which means that the fact that you were "fine for 40min last week" has no bearing on this week's dive, where even though the water temp and your wetsuit are the same you suddenly find yourself shivering violently at 20min.

Lastly, you need to consider the correlative relationship between "time of exposure" and "bottom time." It's intuitive - if you think about it - that your progression from "OK to cold" starts at the beginning of the dive and by definition always reaches its maximum at the exact moment you begin your ascent from your max depth. Unfortunately this also just happens to be when you're at the deepest point of your dive, most tired, most low on gas, furthest from shore, furthest from anchor line, most likely to be narc'ed, and pretty much any other "-est" you can think of including highest nitrogen loading, max p02, etc. Even worse would be if you were actually ending the dive due to an adverse situation such as gear failure, bad conditions, buddy separation, low gas, etc. So no matter what, on every single dive, the very point in time when you need to be THE MOST physically and mentally capable of ending your dive safely will ALWAYS coincide with the point in time at which exposure to cold water will have it's GREATEST negative impact on your physical and mental abilities.

There's a reason that we use the term "exposure protection" and not "comfort" to denote the function of wetsuits/drysuits. As PapaBear said, it's a safety thing. The fact that you're also more comfortable is merely a pleasant "side effect" that you experience when your body is protected from the thermodynamic and physiologic effects of exposure to cold water.

 

[mafiajoe]

. Semidry is a waste of money. Double wet suit would probably be better than semidry.

I second that 100%.Semi is a total waste of money.Steamer + jacket is much warmer and less hassles with the zip.

 

[Becca_007]

I have a 6.5mm semi-dry and find 50s to be quite comfortable. High 40s are tolerable for shorter dives but mid-low 40s I get cold.

 

[RJP]

I have a 6.5mm semi-dry and find 50s to be quite comfortable. High 40s are tolerable for shorter dives but mid-low 40s I get cold.

I saw a post on ScubaBoard recently you may find useful:

"I know I saw that post around here somewhere..."

 

[Herk_Man]

You've clearly also not been diving long enough to recognize that "I've yet to die of hypothermia" is not the same as "I've yet to get cold."

But seriously, there is a very real physiologic difference between "I didn't get cold" and "the cold didn't bother me." Cold water (50F water is cold) exerts specific negative impacts on your body...whether you "feel cold" from a comfort standpoint or not. If you and another person of equal size and wearing similar thermal protection are put into 50deg water for 1/2hr, even though you might not "feel cold" your core body temp will drop at the same rate and to the same temp as the other person, who may be shivering violently. Whether it bothers you less than the other guy does not exempt you from the same laws of thermodynamics; conduction cooling is a function of water temp, body surface area, and time.

I'm usually right there with you on most of your posts. But this one I think is not exactly correct. There is scientific proof that different people have different levels of cold tolerance than others. There was a program on the History channel where they did a study using special forces soldiers submerged in ice water and measured their ability to tolerate being cold and wet. After 30 minutes sitting still in a tub of ice water, the soldier still had a normal body temp and was able to function well enough to shoot a moving enemy several times from a distance with very good accuracy.

What made the difference? The soldier was able to control certain bodily functions better than most people and send blood to his core areas to keep warm. He was also able to more readily draw on his stored energy (fat) than the average person to generate heat in his body to stay warm. (And he was not even shivering.)

Another way to look at this is to compare two similar people that are exposed to cold weather. Only one of them is standing still while the other is exercising. The person exercising may actually start to shed layers of clothing because the energy they are expending is warming them, despite the external cold conditions. The person just standing there may start shivering and will be cold and have a dropping body temp because they are not generating internal heat.

In the case of the soldier, he was able to draw on the ability to generate internal energy without even needing to move. So different people will indeed have different tolerances for cold, even in life-threateningly severe conditions.

Now, do I think your average run-of-the-mill scuba diving recreationalist is going to be able to do this kind of thing? Probably not. But it still stands that some will be able to tolerate cold water better than others given the same outer covering.

 

[a22shady]

(And he was not even shivering.)

I also saw that great program. But the differnce was he was Shivering But he was also in one position with his arms around his core. This is a way of helping to insult the core and keep it warm. you want to keep your arms tight as he did to maintain tempeture. The differnce between him and Diving is your constantly moving as is the water. No matter how good a wetsuit water does still transfer. When he was in there he was still(Shaking) but in one place allowing the warmth to stay inside. With Diving you can not just sit there with arms folded well you could but wouldn't be a good dive. Save yourself the effort and Find a Used Drysuit. You will be happy you did.

 

[Herk_Man]

I also saw that great program. But the differnce was he was Shivering But he was also in one position with his arms around his core. This is a way of helping to insult the core and keep it warm. you want to keep your arms tight as he did to maintain tempeture. The differnce between him and Diving is your constantly moving as is the water. No matter how good a wetsuit water does still transfer. When he was in there he was still(Shaking) but in one place allowing the warmth to stay inside. With Diving you can not just sit there with arms folded well you could but wouldn't be a good dive. Save yourself the effort and Find a Used Drysuit. You will be happy you did.

He was also wearing nothing but his skivvies. You are missing the point here. It was alleged that regardless of the individual, if a person is submerged, they will lose body temp at the same rate. This is incorrect. One person may have a better tolerance for cold based on their ability to draw on internal energy in one form or another.

The method that the soldier used may not apply specifically to scuba but another method might, that is also conducive to diving. Basically what you are saying is that this soldier would not be able to survive while scuba diving better than your average scuba diver. I think that is clearly incorrect. What method he uses to improve his tolerance while diving will most likely differ from the method he used in the ice water tub but he will still be able to keep his core temp higher than someone not using those techniques.

Simple logic.

And to keep this on topic I think that everything the OP needs has been said. Either suck it up and buy a wet suit or determine on your own whether your personal ability to tolerate cold conditions will make a wet or semi-dry option viable.

 

[tmi116]

I have dove wet for a few years in 40 to 50 water with a 7mm farmer john. cold is cold its sucks its not enjoyable even if it is tolerable SO..... I picked up a used dry suit from a guy on here for $525 and now I can be dry have fun and extend my season... I WIN!!!!