is an 8/7 wetsuit inappropriate for warmer water?

[mjatkins]

Same reason you sweat when the air temp is below body temp. Because you generate heat that the body needs to expel.

But in open water knowledge session #2 we learn that water dissipates heat much quicker from our bodies than air (the DM materials say 20 times faster due to conduction). That is why 80 degree air feels warm, while after a while even 80 degree water feels cold. This is the whole reason behind wetsuits, is it not?

 

[g1138]

Although I have seen absolutely no evidence to suggest this is even remotely possible, I will take you at your word that you have a way to gauge the temperature of the water coming out your farmer john. And because of your custom suit is incredibly efficient, you are able to heat the water in it to a greater temperature than your own body.

Back to your original offering about him "boiling" in it. Do you expect he will also be crawling through kelp in said super suit? Or as a general rule, do you think he will be just fine and comfy in his suit of choice?

OK hold on.
I didn't mean to be literal with my term boiling.
And I will admit and clarify that the hotter than pee water exiting my suit was on occasion. (I missed this point admittedly)
There are times when I come back in from a kelp crawl feeling very hot and that's when I get water exiting that feels quite hot on my ankles.

To your above post to SC_Hoaty. Water dissipating heat does nothing if your suit doesn't allow any fresh ambient water to rush in.
Wetsuits were made to keep water from flowing hence insulating you. It's why you SHOULD have warm water exiting your suit when you step out (now I'm not saying hotter than body temp though ;P)

It's like heating a pot of water VS heating a pot with fresh flowing water.

 

[Searcaigh]

It is all relative depending on the water temps you are used to.

75F = 23.8C if my convertor is working properly, I am wearing my 5mm semi dry, but I do not generate much heat slowly moving around looking for macro subjects in the muck.

I normally dive in 28-30C (82-86F) water and wear a 3mm if doing repetitive dives, or a skin if only making two dives.

Pee incidently should be around 36/37C (98F) as it has just left the body. Diving in water that temperature is horrible having experienced it in summer diving the Persian Gulf, especially when the air temperatures are almost 50C (122F)

 

[mjatkins]

You body is 98.6F.
Hyperthermia sets in when you pass 101F.
With your body keeping homeostasis, ie sweating or shivering, you're only talking about changing temps of 0.1F if your lucky.
You feel yourself heat up because your body is releasing the extra heat. But your core temp is still 98.6F or maybe 98.7F.

So yes your pee may heat up but we're not even talking much.

Now if you're unable to get rid of extra heat, say a thick WELL fitting wetsuit, then your body won't be able to get rid of that extra heat.

I want to clarify that I find it highly unlikey for the OP to overheat to life threatening conditions in the water. I'm saying he might find it a little uncomfortable if he has a custom good fitting suit.
And during the surface intervals he may overheat if he doesn't play his cards right.
But of course there are ways to get comfortable suring SI and in the water. It's just a matter if your willing to put up with fidgeting through a thick 8mm suit.

Just to be clear. We were not talking about the conditions required to heat up your pee. You suggested that the water coming out of your suit was "hotter" than your pee. Can you please explain how that is possible?

Thank you for the clarification that "there are ways to get comfortable suring SI and in the water". Point well made.

Would you mind posting some of the basis for your suppositions, and how they relate to people diving in 75 degree water. If true, they would be of great value to those of us who teach scuba for a living.

Thanks

 

[mjatkins]

it would appear that we were writing at the same time again.

 

[g1138]

Just to be clear. We were not talking about the conditions required to heat up your pee. You suggested that the water coming out of your suit was "hotter" than your pee. Can you please explain how that is possible?

Thank you for the clarification that "there are ways to get comfortable suring SI and in the water". Point well made.

Would you mind posting some of the basis for your suppositions, and how they relate to people diving in 75 degree water. If true, they would be of great value to those of us who teach scuba for a living.

Thanks

Sure thing. I know we got off track from pee in the above posts.
Back onto pee!
For certain times when the water exiting my suit feels hotter than my pee, I don't know if that's actually the case because I never actually measured the temp of said water or my pee. I don't even know if pee is body temp to be honest, do you?

It is my opinion that it has gotten hotter than my pee during certain dives when I exited onto shore and felt the water drain out my suit, down my ankles and into my booties.
During those dives I was kelp crawling through stringy Giant Kelp and had to untangle myself several times, buddy couldn't help me because we were surrounded and turning around would only get you more tangled.

So I got onto shore feeling hot and drained. The exiting water felt hot as well, hotter than the 3 times I peed under water.
And unfortunately my pee doesn't exit my suit readily. Sometimes it leaks slowly out from my zipper, and sometimes it comes out my hood. If I pee during my SI it only collects in my booties and I have to empty it through the bootie zippers. @_@
Sorry to be nitty gritty and descriptive about that.

Edit:
This was in 52F waters at Hopkins in Monterey, CA
And Big Creek Reserve, slightly north of Big Sur, CA (that time it was a mix of bull and giant kelp)

 

[g1138]

it would appear that we were writing at the same time again.

Just our luck eh?

 

[SC_Hoaty]

No, in fact it is my understanding that the skin temperature is always cooler than the core temperature when submerged in cool water. Our body draws blood from the extremities and skin into the core to keep the core warm. Thoughts?

But in open water knowledge session #2 we learn that water dissipates heat much quicker from our bodies than air (the DM materials say 20 times faster due to conduction). That is why 80 degree air feels warm, while after a while even 80 degree water feels cold. This is the whole reason behind wetsuits, is it not?

You are real close to an "aha" moment.

Yes, you lose heat to the cool water. Yes, water conduction of heat is superior to air conduction of heat.

Instead of going into all kinds of heat transfer explanations, think about this scenario. Take a nice warm summer day - say 85 degrees in the shade. Put on long underwear, heavy clothes, and a typical winter jacket. Now do push ups, jumping jacks, or another heavy exercise activity. Can the air next to your skin ever get over 98.6? If not, why would you ever be uncomfortable?

Although water removes heat more efficiently than air, is overheating impossible in water when wearing a heavy wetsuit?

 

[dumpsterDiver]

From reading these posts it seems that few of these divers have experienced hyperthermia when diving. I have. It is horrible for me. The only thing worse than being cold in the water is overheating in a suit while underwater. I find iit EXTREMELY claustrophobic and I have approached panic from it on a few occasions.

I almost always dive with a hood, even when the water is in the low 80's but when we approach the upper 80's, the hood has to go, especiallyy if I am wearing a full 3 mm suit. Many dives I have had to pull back the hood during the dive because the bottom temps are warmer than expected.

It is quite possible to overheat in water that is below your body temperature.

An 8-7 mm suit in 75 degree water and no hood will probably work, but who wants to wear all that lead and such a thick heavy suit?

 

[Karibelle]

Sure thing. I know we got off track from pee in the above posts.
Back onto pee!
For certain times when the water exiting my suit feels hotter than my pee, I don't know if that's actually the case because I never actually measured the temp of said water or my pee. I don't even know if pee is body temp to be honest, do you?

It is my opinion that it has gotten hotter than my pee during certain dives when I exited onto shore and felt the water drain out my suit, down my ankles and into my booties.
During those dives I was kelp crawling through stringy Giant Kelp and had to untangle myself several times, buddy couldn't help me because we were surrounded and turning around would only get you more tangled.

So I got onto shore feeling hot and drained. The exiting water felt hot as well, hotter than the 3 times I peed under water.
And unfortunately my pee doesn't exit my suit readily. Sometimes it leaks slowly out from my zipper, and sometimes it comes out my hood. If I pee during my SI it only collects in my booties and I have to empty it through the bootie zippers. @_@
Sorry to be nitty gritty and descriptive about that.

Edit:
This was in 52F waters at Hopkins in Monterey, CA
And Big Creek Reserve, slightly north of Big Sur, CA (that time it was a mix of bull and giant kelp)

Okay.

1. Pee IS body temperature. WHAT ELSE COULD IT BE.

2. You pee IN YOUR WETSUIT during your SI? That's just gross. Take your wetsuit down, pee OUTSIDE of your wetsuit during your SI. Outside.