-- Last Updated: Oct-01-12 10:04 AM EST --
For training purposes in cooler weather:
ANY material can be overloaded by sweat
- i.e. going all out, racing, will soak the material
Those breathable garments on the market work
on water vapor, not on sweat droplets, getting out.
http://www.examiner.com/article/kayak-clothing
IF a material lets sweat droplets out
- it is not waterproof to begin with.