well forst what is the difference between the two, and
what is a good thickness for the pacific ocean, and
how does 3/2 or 6/5 differ from 5mm or 7mm, wut r the two numbers
thanx
Hi Tristan,
With a wetsuit, you get wet; with a dry suit, you stay dry (hopefully). Water is a much more efficient heat transmitter than air -- you'll get much colder much faster when in water than you will above water in air, even when the air and the wtaer are the same temperature. In order to protect you from the heat loss associated with being in the water, you wear some type of exposure suit that reduces the speed which your body losses heat - generally either a wetsuit or a drysuit. Both forms of exposure suit actually utilize air's inefficiency in transferring heat in order to keep you warmer.
A wetsuit contains thousands of little bubbles of air trapped within the neoprene -- these bubbles of air slow the cooling you'd experience without the wetsuit. A good fitting wetsuit fits very snugly so that even though a slim layer of water will seep into the suit and surround your body, the water shouldn't be constantly rushing in and out -- the result is that your body heat relatively quickly warms the thin layer of water between you and the suit so additional cooling is slowed, which further allows the neoprene bubbles to perform their insulation function. If the wet suit fits poorly, you'll have a lot more water transfer in and out of the suit which will speed how fast you get cold.
A dry suit is kind of like a giant bag that seals tightly enough around your body to prevent any water from entering (though sometimes they leak a bit). Most drysuits had attached socks or boots so there are seals around only your wrists and neck which have to keep the water out of the otherwise airtight bag. You wear an undergarment (like long pajamas) inside the drysuit to keep you warm. Since air is trapped inside the drysuit, and air is a much more inefficient transmitter of heat, a drysuit tends to keep you warmer than wetsuits provided it fits properly and you have suitable undergarments.
As to what's agood thckness for the Pacific -- that will depend an awful lot on where you're diving, what types of dives you like to do, and your own personal thermal characteristics (some people get colder than others -- the differences can really be dramatic). With drysuits there's not reallly a thickness -- you change the type and or thickness / layers of your undergarments according to conditions. With wetsuits, there is the consideration of the style as well as the thickness. As you posted, the 5mm or 7mm is the thickness (in milimeters) of the suit - basicallly the thicker the more insulation it will provide. Those suits that are 3/2 or 6/5 usually offer a slightly thicker neoprene in your torso / core area, and a thinner neoprene in your extremities like arms and legs -- keeping your core warm helps keep your whole body warm; a thinner material on your extremeties helps with your freedom of movement (you don't feel quite so much like a sausage). I mentioned above that the type of wetsuit also matters -- in colder waters where wetsuits are used, some folks like to use a "farmer john" suit which consists of a sleeveless overall-style piece and a separate jacket / chest piece over the overalls. If the farmer John were 7mm, you'd effectively have 14mm over most of your core but 7mm over your extremities.
I can't stress how variable your sensitivity to cold can be. My wife an I dove years ago in Monterey, CA with 7mm farmer johns -- a 45 minute or so dive in water that was likely somewhere around 50F resulted in me being a bit chilly by the end of the dive and my wife being super cold; I've seen others who seem to be comfortable enough in a one-piece 7mm (so not even having the extra thick 14mm core coverage).
If you're new and looking to buy some exposure protection, I'd definitely say get in a few dives to assess how you feel in the water with different types of wetsuits, and soak up some of the information on this board that others have shared. You'll generally need to take a separate course to learn how to dive a dry suit safely before most shops will rent you a drysuit (at least in my area), so I think you'll have to experiment with wetsuits for a least a little while.
There are a whole host of other considerations on the type of suit you ultimately might decide for you, but that's waht reading here and talking with other divers is for. Good luck!
Edit: OK - a number of posts beat me to it while typing this monster out - you're getting good feedback from others!
