Well, after wearing this suit for several days of unending rain, I can confirm that it is indeed waterproof. Not only that, but it's actually a comfortable suit to wear for extended periods of time. The elastic waist in the jacket greatly reduces/eliminates any flapping, while the elastic waist on the pants keeps them comfortable for extended periods of time. The pants also have leg expansion zippers which make it possible to pull them on over your boots. The cuffs of the pants have elastic "stirrups" which you can loop under your boot to keep the pant legs down in place. Heat resistant material keeps the lower legs from melting on hot engines/exhaust. The jacket has Velcro sleeve cuffs so you can tighten them up, and the base of the jacket has a pull cord which helps keep water and air from coming up underneath. There is a heavy duty storm flap over the main zipper, and the high collar is lined with corduroy which makes it nice and comfortable. A large rear exhaust vent helps to let hot air out, and reflective piping helps increase visibility in adverse weather conditions. Two front pockets on the jacket have Velcro flaps which should keep the contents dry.