Layers under the drysuit

[brambor]

As my second season in a drysuit approaches I am slowly reflecting on last year and trying to improve on the past winter.

I am trying to bounce some ideas off here to see what comes back:

Neoprene pants under the drysuit.

Last year I started with fleece pants and fleece top under my drysuit. Then I switched for a one piece fleece garment. This improved the overall insulation seal. I found, however that when the weather and water got really cold I needed more insulation on below my waist and added fleece pants in addition to the one piece fleece garment. This year I think I will try neoprene pants under the drysuit.

... as the weather warmed up in the spring I switched back to two piece insulation but this time it was thin wool underwear bottoms and tops. I think perhaps for this spring the combination of neoprene pants and wool upper will do the trick.

Use of Vapor Barrier Shirt

Use of Vapor Barrier garments is somewhat old school but it seems to work for me in certain situations... especially winter hiking. VB shirt for example will trap heat your body produces. Keeping this fact as a consideration I thought that perhaps a VB shirt as first layer, then thin wool upper garment as a second layer and then drysuit over this. The idea being that the insulation between your body and drysuit will not get wet from your perspiration and will continue its insulating properties.

The unknown for me is the behavior of VB during paddling motion. In hiking, a thin film of perspiration will stay under the VB and that will in turn prevent further release of sweat, effectively reducing dehydration. I wonder if anyone here tried this under the drysuit?

[bob budd]

...under the drysuit...

Personally I wouldn't want something as clingy, etc. as neoprene under the dry suit. I would advise two-piece as it allows you to adjust for warmer days (above the cockpit) and colder water (below the waist). I find the PFD provides alot of insulation and also blocks breathability so I carry extra pullovers if I expect to be out of the boat for much time. Because the PFD blocks breathability it can help to open the drysuit on breaks. I accidentally ended up with an oversized paddling jacket that slips over the PFD, a great on-the-water-change option.

...Vapor Barrier Shirt...

Each of us is different, I wouldn't paddle in temperatures where I would need more than one heavy weight upper and lower fleece. Remember that if you stop any moisture under the suit will have chilling effects.

[brambor]

...Vapor Barrier Shirt...

Each of us is different, I wouldn't paddle in temperatures where I would need more than one heavy weight upper and lower fleece. Remember that if you stop any moisture under the suit will have chilling effects.

Hi Bob,

but if there is a dry, insulating/warm layer between the VB and the drysuit will it reduce the chilling effect?

[Suz]

Brambor's comments in bold

As my second season in a drysuit approaches I am slowly reflecting on last year and trying to improve on the past winter.

I am trying to bounce some ideas off here to see what comes back:

Neoprene pants under the drysuit.

Last year I started with fleece pants and fleece top under my drysuit. Then I switched for a one piece fleece garment. This improved the overall insulation seal. I found, however that when the weather and water got really cold I needed more insulation on below my waist and added fleece pants in addition to the one piece fleece garment. This year I think I will try neoprene pants under the drysuit.

... as the weather warmed up in the spring I switched back to two piece insulation but this time it was thin wool underwear bottoms and tops. I think perhaps for this spring the combination of neoprene pants and wool upper will do the trick.

Definitely don't wear neoprene under the drysuit. If you are cold add layers. Neoprene will create a build up of sweat under the neoprene which will not be able to leave the drysuit.

Use of Vapor Barrier Shirt

Use of Vapor Barrier garments is somewhat old school but it seems to work for me in certain situations... especially winter hiking. VB shirt for example will trap heat your body produces. Keeping this fact as a consideration I thought that perhaps a VB shirt as first layer, then thin wool upper garment as a second layer and then drysuit over this. The idea being that the insulation between your body and drysuit will not get wet from your perspiration and will continue its insulating properties.

The unknown for me is the behavior of VB during paddling motion. In hiking, a thin film of perspiration will stay under the VB and that will in turn prevent further release of sweat, effectively reducing dehydration. I wonder if anyone here tried this under the drysuit?

Vapor Barrier shirt to create a thin layer of sweat???? I don't understand how a layer of sweat prevents further release of sweat....

Either way, both of your ideas end up creating moisture in the drysuit which is what you want to avoid.

As for wool, sweaty people who wear wool in a drysuit don't remain dry. Although some people find wet wool to be "not uncomfortable" (but not especially comfortable either). Wool when wet will still cool you off under a drysuit when it is work w/o wicking garments. I can use wool under a drysuit as I do not perspire a lot. Others find that they get too much moisture built up.

The key to remaining comfortable in a drysuit is to keep the moisture build up to a minimum. So, wicking layers are the best.

Remember, unlike hiking or skiing, there are no pit zips in a drysuit.

[brambor]

Vapor Barrier shirt to create a thin layer of sweat???? I don't understand how a layer of sweat prevents further release of sweat....

Suz,

Have you ever used Vapor Barrier shirt or do you actually know how it works? If not then please reduce your number of questions marks... ;-)

Vapor Barrier is a barrier that prevents vapor to escape. So in essence it traps heat (and sweat). It might make people feel a little bit 'clammy' but it depends on the individual. An interesting effect of this is that once it traps the sweat, your body does not continue the production of perspiration.

If you prevent the release of perspiration to your insulating layer then you have (kind of) prevented the buildup of moisture in the drysuit. Your insulation stays dry.

[brambor]

for example in winter hiking:

One of the hurdles is to keep your socks dry so that they keep you warm. There are several ways to approach the problem but an old method (used first in WW1) is to put vapor barrier (plastic bags) onto your foot, then socks and then another plastic bag. It keeps the socks dry. It keeps you warm, there are no pit zippers... or anything like that.

One has to take their boots off at the end of the day and dry their feet...failure to do so could produce 'trench foot' (I think the term was coined in WW1 because of this)

[bob budd]

if there is a dry, insulating/warm layer between the VB and the drysuit will it reduce the chilling effect?

My opinion is that anything that would trap moisture inside the suit is a bad idea. While you are working moisture may or may not make you uncomfortable. When you are at a break the moisture evaporates and cools you off. If you slow this process you are less cool for a longer period. The key is what makes you comfortable. I've been fortunate that I am relatively immune to moderate swings of temperature and find most paddling to be moderate activity wherein I can put on what makes sense for the day and I don't need to worry. I've paddle with others that need to adjust their layers as most days unfold. If you are trying something new you can carry a known solution in the hatch and change if its not working.

[rick stoehrer]

Brambor -

i wear a thin layer of wicking fabric clothes (polypro or whatever the nom du jour is now, ems, rei, beans...they all have some) and then additional wicking layers on top of that to account for the temp.

the first layer wicks the moisture away from me and to the layers that are closest to the suit...that layer of clothes will inevitably be damp at the end of the day as the suit generally doesn't "breathe" as well as some of the undergarments but in any event, you're warm, dry and cozy.

i do the same with socks..thin wickers and then some woolies work for me just fine.

and neoprene underneath won't work...neo suits work on the idea that you trap water and then your body heat warms the trapped water....which on a cold winter day isn't going to work too well, too long.

i try to make sure i have a hat - if you can keep your head warm, you'll stay warmer. gloves or pogies, a rasdek to toss on if it's still chilling and then a cuppa tea in the day hatch and off you go.

and pee before you put all that on!

[brambor]

theoretically, moisture will not evaporate when wearing VB. In reality it will probably evaporate very sloowly and therefore not chill you.

This is only for the sake of discussion. I want to reiterate that I have not tried this while sea kayaking.

if there is a dry, insulating/warm layer between the VB and the drysuit will it reduce the chilling effect?

My opinion is that anything that would trap moisture inside the suit is a bad idea. While you are working moisture may or may not make you uncomfortable. When you are at a break the moisture evaporates and cools you off. If you slow this process you are less cool for a longer period. The key is what makes you comfortable. I've been fortunate that I am relatively immune to moderate swings of temperature and find most paddling to be moderate activity wherein I can put on what makes sense for the day and I don't need to worry. I've paddle with others that need to adjust their layers as most days unfold. If you are trying something new you can carry a known solution in the hatch and change if its not working.

[brambor]

Rick,

Yeah, the neoprene idea might not work. Are you saying neoprene's insulating properties aren't working when dry?

Brambor -

and neoprene underneath won't work...neo suits work on the idea that you trap water and then your body heat warms the trapped water....which on a cold winter day isn't going to work too well, too long.

[Phil Allen]

Rene-

The problem I see with the vapor barrier approach is that the sweat generated (but not evaporated) is free to run downhill. Usually to our feet. I know folks that have used their drysuits on hot air but cold water days that ended up with several ounces of liquid in the booties. Again, this is dependent on how much you sweat.

That said, a related approach to your vapor barrier idea is to pull windproof, water resistant clothing over the drysuit to slow the evaporative cooling when you're cold, or stopped paddling and not generating heat. Things like rain pants & storm cags work nicely for this.

As Bob said, it's all a balance. Too hot, or too cold, humans don't perform well.

Phil

[bob budd]

Neoprene is a foam and all foams provide some insulation between the two sides of the foam. A neoprene suit can be very hot on a cool sunny day. How well a neoprene suit works when wet depends alot on how well it fits, i.e. when you go for a swim water will flush in and out of the suit more or less depending on how tightly it fits.

[Brian Nystrom]

Rick,

Yeah, the neoprene idea might not work. Are you saying neoprene's insulating properties aren't working when dry?

That sounds like what he's saying and even it it's not, it's worth mentioning that this is a very common misconception about neoprene. The truth is that dry neoprene insulates better than wet neoprene and the layer of water that a poorly fitted wetsuit allows in reduces its insulating ability, it does not increase it. Wetsuits provide insulation despite the fact that they may let in water, not because of it. The insulation is provided by the gas trapped in the bubbles in the neoprene. The closer the fit of the suit and the less water seepage it allows, the better. That's why garments like the ubiquitous "Farmer John" provide very poor upper body insulation compared to a full wetsuit.

Getting back to the original questions:

Is your dry suit made of breathable fabric? If so, why would you defeat the purpose of that breathability by wearing a vapor barrier garment or neoprene (which is is a vapor barrier, too) underneath it? It makes no sense. If your dry suit isn't breathable, wearing a vapor barrier against your skin - if you can stand the feeling - will keep your insulating layers from getting wet, which is a real problem in non-breathable dry suits.

If you're wearing a vapor barrier and you're working hard, you are going to sweat and get soaked, though how bad it will be varies from one individual to the next. My understanding of vapor barriers is that they're most effective for sleeping in cold conditions, as they prevent insensible perspiration from getting into the insulation of a sleeping bag and condensing, where it can dampen the insulation and even freeze, reducing it's effectiveness.

Vapor barriers are pretty much an "old tech" solution to a problem that was largely solved by the introduction of wicking fabrics and waterproof/breathable outer garments. Pick whatever works for you, but mixing "systems" isn't a good idea, IMO.

I'd also like to make on comment regarding Suz's criticism of wool. I've worn wool and synthetics from head to toe and I've found that while I like synthetics for my upper and lower body, wool works better for me for my hands and feet (inside dry gloves and a dry suit, respectively). Synthetic fabrics just seem to flatten out and lose their insulating ability in these applications.

[Suz]

I'd also like to make on comment regarding Suz's criticism of wool. I've worn wool and synthetics from head to toe and I've found that while I like synthetics for my upper and lower body, wool works better for me for my hands and feet (inside dry gloves and a dry suit, respectively). Synthetic fabrics just seem to flatten out and lose their insulating ability in these applications.

I love wool and definitely love it for my feet and hands and personally I like wearing it on my body.

I think I am a walking advertisement for Smartwool and Icebreaker:) summer and winter. My favorite shirts are now the wool t-shirts from Smartwool.

Suz

[Suz]

The unknown for me is the behavior of VB during paddling motion. In hiking, a thin film of perspiration will stay under the VB and that will in turn prevent further release of sweat, effectively reducing dehydration. I wonder if anyone here tried this under the drysuit?

Still don't understand the concept of a thin layer of sweat that prevents further release of sweat effectively reducing dehydration. Please explain.

[tyson]

Still don't understand the concept of a thin layer of sweat that prevents further release of sweat effectively reducing dehydration. Please explain.

I previously read the page that the VB/sleeping bag/tent guy has posted that was linked in this forum. He doesn't claim that a VB reduces sweating. He claims that a VB reduces incidental drying of skin by raising the humidity level next to the skin. Cold dry air draws moisture out of the skin. He promotes adjusting your insulating layers to prevent sweating.

My two comments would be:

- I sweat a lot. This is not for me.

- Its not easy to adjust insulating layers that are inside a dry suit to prevent sweating when out on the water.

Cheers!

Ty

[brambor]

Still don't understand the concept of a thin layer of sweat that prevents further release of sweat effectively reducing dehydration. Please explain.

When you sweat you get dehydrated because it evaporates from your body.

If you can reduce the amount of sweat evaporating from your body - you will reduce the level of your dehydration.

Under Vapor Barier your sweat can not evaporate. Therefore you get hot or warm (depending on the outside temperature) but you won't be dehydrated (discounting evaporation from your mouth and head). If your sweat can not evaporate, trapped right on your skin, you body will not produce more sweat.

Another interesting byproduct of this is that because you don't bring fresh air under the VB there is no way bacteria can operate and die (stinking clothes) and therefore whatever is under the VB does not stink until you expose it to fresh air.

[tyson]

When you sweat you get dehydrated because it evaporates from your body.

The web page I recently read (that was linked from a recent thread on this forum) made a distinction between sweating (your body's reaction to being too warm) and the moisture that evaporates from your skin in low humidity environments even when you are cool enough to not sweat.

Regardless of the humidity level next to your skin, if you are too warm you will sweat. If you are cool, you will not sweat. Sweating always leads to dehydration if fluids are not replenished.

[spider]

I know that I am not a vapor barrier believer, but mostly from the hiking winter camping community where some people are strong believers in it.

For me I have found moisture brings cold quicker than dry does.

In a way we are creating micro climates in our suits. If cold I rather be dry and cold, as opposed to wet and cold.

Dry and cold you can always throw a jacket on over your suit at breaks and get some more heat.

If I'm wet and cold and throw on a jacket it mostly just brings the wetness closer to my skin.

I think there are all type of stats about water conducting heat 25% faster (or more) away from the body.

I think for stench factor I suppose if we vacuum sealed our feet into a vapor barrier it might not stink , but since we can't quite get rid of all the air it does indeed 'stink to High Heaven"

I like wicking layers but they can only wick in relation to the relative humidity around them. So the more a fabric is restricted from "breathing" the quicker it will wet out and saturate.

then it just becomes another wet fabric conducting heat away from your body at an increased rate.

playing safe I could put in my disclaimer now...but that is my understanding.

I know some vapor barrier folks are quite passionate about it's merits.

[brambor]

Although I have used VB many times, I have to say that I have NOT used it most of the time. I would say that I am not a 'zealot believer'.

For starters, let's not try to create solution if there is no problem to solve - I'm slightly relating to Brian N's comment.

So, the question we could be asking first is: Are we really dry under our drysuits with our wicking garments?

I have to say that under ideal sunny and windy conditions, if I don't exert myself to the point of sweating - I am dry under the drysuit. Any other time (more often than the ideal conditions) my insulating layers are wet from perspiration even though they are 'wicking' sweat away. The fabric is still damp or wet. This does not present any problem if I return safely to the harbor the same day. But if I actually capsized, lost my boat and drifted away... I am worried that I would not get the necessary warmth out of my insulating layers.

Also if I camped out overnight in the winter, perhaps in a sleet or snowstorm, I would have a hard time drying my insulating layers before I had to put them back on in the morning.

[tyson]

Also if I camped out overnight in the winter, perhaps in a sleet or snowstorm, I would have a hard time drying my insulating layers before I had to put them back on in the morning.

I've heard that in this case you sleep with them on. They will be dry(er) in the morning.

[Phil Allen]

....The fabric is still damp or wet. This does not present any problem if I return safely to the harbor the same day. But if I actually capsized, lost my boat and drifted away... I am worried that I would not get the necessary warmth out of my insulating layers.

...

As I see it, really we should be thinking not about this as a paddler in a boat, but as a swimmer who recently was in a boat. Drysuits work because they keep water out of the insulation and the insulation slows the cold migrating from the environment into our bodies. While swimming this works less well, as the air and insulation is compressed, and the transfer of heat from out bodies to water is faster than to air. I'm not sure having a thin layer of H20/very hydrated air at the skin surface is going to help reduce the heat transfer under those circumstances.

As for dry insulation layers, bring extras. Some folks go as far as changing at lunch. Think of your kayak as a sherpa for several expedition size backpacks. No problems with carrying extra clothes, camp stoves, thermos bottles and or shelters on a winter day.

Phil

[brambor]

Good thinking Phil. Food for thought.

As I see it, really we should be thinking not about this as a paddler in a boat, but as a swimmer who recently was in a boat. Drysuits work because they keep water out of the insulation and the insulation slows the cold migrating from the environment into our bodies. While swimming this works less well, as the air and insulation is compressed, and the transfer of heat from out bodies to water is faster than to air. I'm not sure having a thin layer of H20/very hydrated air at the skin surface is going to help reduce the heat transfer under those circumstances.

As for dry insulation layers, bring extras. Some folks go as far as changing at lunch. Think of your kayak as a sherpa for several expedition size backpacks. No problems with carrying extra clothes, camp stoves, thermos bottles and or shelters on a winter day.

Phil

[bob budd]

One reason you get damp/wet under the dry suit is because breathables don't work under a PFD or in a cockpit.

If you find yourself cold in your drysuit you might be warmer if you introduced a bit of air.

If you are in the water its a whole different ball game than when you are paddling or lounging at the beach. If you dressed for extended (hours?) immersion you would be too warm for most activities.

[EEL]

I found, however that when the weather and water got really cold I needed more insulation on below my waist and added fleece pants in addition to the one piece fleece garment.

Just some observations that may not apply. Since your legs and lower torso are protected in kayak, it should be easy for them to stay warm..assuming head/core is warm. If you keep you legs relatively flat most of the time, perhaps it is the cold hull that is chilling your legs. You might try slipping a foam sleeping mat in the cockpit so the legs rest on it. I paddle with my legs flat on the hull essentially all of the time and have found using a foam sleeping pad makes for a very comfy and warm ride. I admit to not having experience paddling much under 30 degrees.

Ed Lawson