definitely NOT waterproof
"they might be great for splashing through a shallow stream or bog but I used them for four days wet wading on the Frying Pan River and they did not keep my feet dry by any means. They are not good for sustained immersion!!!! The Holy Grail of waterproof socks is still unfound. Very disappointing particularly from Simms they must not have used them in sustained submerged application, which is bad for Simms reputation."