Layering a shorty

[MagicChicken]

I have layered a 7mm full over a 2mm shortie for extra warmth in cold waters. Combined with neoprene socks, there isn't much water flowing in and out. The neoprene layers themselves will not keep you warm. The warm water inside the suit will.

The neoprene of a wetsuit (1) traps water around your body, and (2) slows its cooling rate.

I'm going to dive in TCI next week. The plan is to layer a 2mm shortie and a 2mm full.

- insulation : either way, I'll end up with 4mm oevr my torso and 2mm over my limbs

- water flow : I would presume the shortie (unlined seams) under the full would be better, however Pearldiver07's idea would suggest that the gaps created by the seams could lead to more water flowing in and out.

As a scientist, I'd love to make a few experiments

Anyway, the full on top feels too tight (a big no no) so I'm gonna go with the shortie over the full suit.

 

[Sinbad the Diver]

I have been pondering this (slow time at work with hollidays and all). MagicChicken, as a scientist, how bout this angle when comparing layering 2 suits to a single suit.

The goal of the wetsuit is to trap water around your body and slow it's cooling rate. Would the fact that there is a layer of water (colder water) trapped between the layers change the value of the inner layer. For example, the water around you is 80 deg F, the external water is 60 deg F. Would the water between the layers be somewhere in between, lets say 70 deg F for arguement. From there, assuming you have the thicker suit underneath you could potentialy get more value out of the layering than a single suit. On the other hand if the thinner suit was under, you get less.

hmmm....I think you are right, an experiemnt is in order. Wonder if I could convince one of the wetsuit companies to give me some gear to do this experiment for them?

 

[MagicChicken]

Hey, I'm a molecular biologist, not an engineer or a physicist

You made an interesting suggestion.

Water has a high specific heat capacity, e.g. it takes a lot of energy to change its temperature. As a consequence, it will "suck up" the caloric energy. Insulators, like air, have a very low specific heat capacity.

A water compartment between two neoprene sheets shouldn't have any insulative value. Or, a least, very little.

I would rather think that it's best if the second neoprene layer fits tight on the first to insure maximal insulation.

Could some of the more experienced divers on this board share some empirical data?

 

[RAWalker]

I've used a 2mm shortie under a 3mm Hyperstretch full. The order was because the shortie would not fit over the full.
Based on the fact that wetsuits work on two factors insulation and water flow control I feel this order does have an advantage of better flow control as compared to insulation thickness alone with the shortie over the full.

 

[Ms.DiverUSA]

I wear a Wetwear 3mm full suit with a 3 mm shorty on top. Fit is a big reason for why the extra piece should be worn on top. My suits were custom made so that I could wear the 3mm full jumpsuit all year around...so that piece fits me perfectly. Then when I do my colder diving I wear the shorty (which was made a tad bit bigger to go over the jumpsuit) on top. If you can fit the shorty underneath the full suit...than your full suit is to BIG!!! The arms in both my suits are a 2mm so when I have both pieces on it is only 4 mm is my arms.

 

[pelan-pelan]

Been there, done it, got the tee shirt.

It depends on the fit and weight and material of the two suits and the shape of the person.

Discomfort and a feeling of clothing claustrophobia will lose several degrees of warmth due to stress.

Try either way and then choose. Wear a different suit - then try the combination either way.

As for the tee shirt wot I got - I wear that under a coat.

 

[Charged]

I am from Kentucky. My OW class traveled to Florida to take our certification test. We were just north of Gainsville, FL at the infamous Ginnie Springs (http://www.ginniespringsoutdoors.com/). The water temperature was roughly 72 degrees. My instructor advised us to put on a 3mm farmer-john followed by a 3mm shorty. The attached photo is of us performing the skills test. I am on the far right and my instructor with his back to us as we were arched around him. You can clearly see the suit configuration Im wearing in this shot. Yes, the signal I was giving was accurate...I was cold. Keep in mind though, I had been just sitting there for quite sometime waiting on my turn. During the required SSI fun-dive, however, body heat was generated and I was fine.