Waterproof jackets aren't essential in outdoor sports at all. Staying dry is important, but you can get just as wet from inside by sweating, so your waterproof layer should be able to breathe. Some people swear by Gore-Tex, while others say it doesn't work efficiently enough.
There are two alternatives to waterproof or waterproof breathable jackets that I am aware of:
One is to wear a breathable, coated, but not seam sealed nylon windbreaker jacket such as the Sierra Designs Microlight Jacket http://www.travelcountry.com/shop/Action/Vendor_Prod/ProdId/5327/RefId/29/RefType/Affiliate,
and utilize a lightweight umbrella http://www.travelcountry.com/shop/SessionId/c91d8a90da74048cc3902dad4430a56b/Action/Category_Prod/ProdId/5451 designed for hiking.
The second option is to wear a fully coated and seam sealed nylon or UL sil-nylon poncho. http://www.campmor.com/webapp/wcs/stores/servlet/ProductDisplay?productId=39199371
Either system will provide ample protection from rain while allowing sufficient air flow to prevent soaking from your own sweat.
But of course that only works for hiking, backpacking, fishing, etc. If you're skiing when it's snowing and wet or kayaking in the cold and rain obviously you need a rain jacket.
· 1 decade ago