Sage 8123-4 TCR

Fall/Winter steelhead weather can mean rain and lots of it. 
The word "rain" turns most people off, because they associated it with discomfort. However, rainy days don't have to be uncomfortable, 
if you dress properly. 
Many rainy days can be beautiful. 
Everything is washed and clean. Rain softens the edges of the landscape. It dampens sound and a rainy day on the river can be one of personal intimacy. But the best reason to fish in the rain, is that steelhead are more aggressive on cloud-cover days.
If you dress correctly, you can be comfortable, even during long days in cold, wet weather. If you don't dress correctly, you can get cold & wet.  As you lose thermal energy, your motor skills will suffer.  Warm muscles perform better than cold ones.  Dress to keep yourself warm and dry.  Keeping your skin surface free from dampness is one of the biggest keys to staying warm.  
Many people think that preparing for rain only means the addition of a rain coat and chest high waders. 
The selection of these items is very important, but what you wear under this outer layer is also very important.  Any moisture trapped within your clothing will conduct heat away.  This means that you not only have to keep the rain out, but your clothing also has to have the ability to disperse and dispel
your own perspiration. 
When dressing for cold or wet weather fishing; dress from the inside out.
The layer of clothing next to your skin is the one you will feel all day.

Maximum perspiration zones are your arm pits, groin and feet.  All these areas need special clothing.  Your inner layer should be made from synthetic material for maximum comfort.  It should be soft and designed to wick moisture away from your skin.
Never wear cotton clothing under your waders.
Cotton retains moisture and has very little insulation value when damp.  It also becomes a medium for fungal infections.  The organisms that cause infections such a jock itch and athletes foot can not live in synthetic fabrics.  Synthetic materials tend to  "pass-through", rather than "retain" moisture from perspiration.   Nylon, acrylic and polyester do not retain as much moisture as cotton, silk or wool.  Dressing with layers of Synthetic material can

 further customize the wicking of moisture away from your body.    Pay special attention to the layers that cover your legs and feet.  These extremities are the ones that will be immersed in cold water.  When water temperatures are below 50-degrees double layering is recommended.  Water temperatures below 40-degrees demand heavier double-layering.  Nylon fleece such as Dutch Harbor becomes much more efficient with a layer of Capilene under it.  A layer of Patagonia Mid-weight Capilene next to your skin with a layer of Simms Heavyweight WaderWick over it can keep you roasty-toasty during what would otherwise be inhospitable climatic conditions.  Heavyweight WaderWick is the best cold weather insulation that we have found.

Pay special attention to your socks. Water runs down hill and some of your body perspiration will collect at your feet. This happens much less with breathable waders, but is still a factor, especially if you are hiking between pools.  There is no way for wader feet to breath inside your wading shoe.  Wader feet are still made from insulating, but non-breathable neoprene.
We like thick wool/nylon blend socks that have a knitted loop pile on the inside which gives them the capacity to retain a lot of loft, even with the squeezing pressure of your waders around them. They act as a reservoir for migrant perspiration but help keep it away from your skin.  
Of this type, Outdoor Socks by Fox River are the best we've tested.  They are knee length so provide another layer of insulation for the lower leg.  Remember, all socks are made from knitted yarns which tend to wash-out as you launder them, thereby loosing loft and insulating qualities.  Replace them often for maximum comfort.  

Your outer layer is your first layer of defense.
It must be water-proof, but it too must be able to dispel any moisture that might collect inside it.  This is accomplished by a special membrane sandwiched between two layers of protective fabric.  This membrane is porous so it can breath.  The pours are of a diameter that allow smaller gaseous molecules to escape, but will not allow larger liquid molecules to enter.  Non-breathable waders and rain jackets have all but disappeared 
from the steelhead fly fishing scene in favor of newer technology fabrics such as:  Gore-Tex.