so what company makes this wonder material you speak of?
i'd like to talk to them and see if i can borrow their flux capacitor or maybe their warp drive.
they are able to fold the space time continuam and suspend all laws of physics.
Thinsulate retains 80 percent of its insulating capacity even when wet.
wet is the key word here, and your not realy understanding the manufacturer's definition of wet.
a wet fabric is one that has been breifly exposed to liquid. like being sprayed with a garden hose for a second.
a soaked or drenched fabric is one that has been completely saturated in a liquid. like dunking a shirt or towel into a bucket of water for a minute and then pulling it out.
submerged is when a fabric remains in the water and hence every pore of that fabric filled with water.
in a wetsuit, the insulation is not provided by the rubber in the suit. if that were so then wetsuits would be made of rubber and not neoprene. the insulation is provided by the nitrogen bubbles in the neoprene. those bubbles create air spaces within the neoprene. those airspaces are insulating you from the water around you. the thicker the neoprene, the more bubbles of nitrogen providing insulation.
in a drysuit, your warmth is created by the same thing, an airspace. your different undergarments provide the varying degrees of warmth in the same manner. they trap air to provide insulation. without air spaces, they completely loose their insulation ability.
if, while wearing thinsulate, you were to jump into the water, and then get back on the boat, the excess water will drain off and due to the nature of the material, the airpockets will help you retain 80% of your heat or whatever they claim. this is because the magic of thinsulate is its design as a hydrophobic material. it doesn't retain water and moves the water to its surface where it can fall away or evaporate. when this happens, the airspaces return and you are insulated.
if your wearing a drysuit and it floods, you have completely lost all insulating properties of the thinsulate. the water has no way to drain off, nor can the fabric push the water to the outside, it has no way to "dry" itself, after all your in the ocean. (think how much deeper the ocean would be if there were no sponges in it)
when completely surrounded by water, as when a drysuit floods, heat loss is via conduction. the water is conducting heat away from the body. since the thinsulate relies on air to provide insulation, and there would be no air in a flooded drysuit, the thinsulate provides zero insulation in a flooded drysuit. unless of course you could pump the water back out.
now, if your drysuit remained mostly intact, it would prevent the outside water from rushing past your body and stripping away any water your body may slightly warm. but the water in your drysuit your body is now expending calories to heat, is efficiently conducting that heat through your drysuit to the colder water outside. it is thermodynamicaly impossible for you to get the water in your wetsuit to 98 degrees. yeah, you can piss in it, but that won't last long. your battling the ocean, and it is the biggest and most efficient heatsink on the planet.
as for any kind of "reflective" materials. these are a thermodynamic flop as well. yes, there are materials that reflect heat just fine on land, but they are reflecting convective heat.
it is impossible to reflect conductive heat.
i don't doubt the salesmen believed the claims he made. but he didn't understand what he was explaining.
the big wetsuit and drysuit manufactures leave their claims at intentionaly misleading.
they used to make flat out false claims, but scuba lab and a few other entities called them on it a few years ago, asking them to explain how they are suspending the laws of physics.
I have flooded a suit before and then stayed in the water completing decompression. Other than feeling wet, I had no issues with being cold. However, that was with 200 gram Thinsulate.
I am just not sure if the 40 will be enough when it's Winter. So, I will switch to the 100 if necessary.
and thats what it realy comes down to. your gonna ignore it or your gonna be misserable. if the suit is flooded, your sucking but unless your diving in some very extreme conditions, you'll live.
in the not so cold months when i dive dry i wear coolmax longsleeve shirt and pants. i don't like feeling the inside of the drysuit on my skin. and it provides a nice layer of insulation while in the water, and is light and cool out of the water.
when its cold, i wear polar fleece. very warm with little loft.
survival when completely immersed in water (flooded drysuit, not bobbing in the north sea in an exposure suit) depends on the water temp and the exposure time, not on what you are wearing. in most cases you have the time to complete deco (dive shouldn't be more than 90 minutes right?). course, not sure how that will work with a rebreather, you can realy rack up the time, but should be able to surface at any time right?
Go hiking in the pouring down rain wearing all wool/polypro and then try it wearing all cotton.
see earlier explanation. getting rained on is completely different from
remaining submerged in water.
wool is naturaly hydrophobic. polypro is a synthetic designed to be hydrophobic. on land both will shed water and retain air for insulation. cotton will not. cotton will retain water and all the airspaces will be filled with water.
80% heat retention while
wet i outstanding. and is only possible above sea level, and not submerged.
a wetsuit will not even provide 80% heat retention. the ocean conducts heat away from your body at to fast a rate.
if thinsulate could provide 80% heat retention while submerged or flooded, then you could wear it instead of a wetsuit.
Edited by BradfordNC, 24 May 2006 - 09:17 AM.
OK, lets make a deal. If you stop telling me how to dive, I'll stop going down to the bus station at 2am to slap d***s out of your mouth.
