Microporus fabrics work because water molecules are larger than air molecules--as long as the "micro pores" in the fabric are less than 10 microns across (the size of water molecules) air molecules can escape while water molecules can't get in. Of course water vapor molecules are smaller than water molecules, so the water vapor escapes with the air.
Hydrophillic coatings are more advanced and therefore more complicated. These coating are composed of a mixture of hydrophobic (water hating) and hydrophillic (water loving) molecules. In the simplest terms, moisture from inside the garment is absorbed through this chemical chain and pushed to the outside, while the surface fabric has pores that let air enter.
So whether you sailing, boating, or fishing, the first thing to look for is the type of breathable fabric. Both work, but as always, you usually get what you pay for.
The next topic will be how the design of the foul weather gear affects it's breathability--even though the fabric is breathable the cut and style make a tremendous difference in effectiveness.
For a complete selection of foul weather gear for sailing, boating, and fishing, visit Whitecaps Foul Weather Gear at www.WhitecapsFoulWeatherGear.com. They have great sale prices, free shipping and offer free merchandise. And their customer service is terrific.
We'd also like to thank Gill, www.Gillna.com for all their knowledge.
