For all the ‘oh there’s a hole in the top of course they let water in’ comments; do you not think it’s a little poor on the behalf of the manufacturer to market a sock as waterproof, and then it not be in use?
A little naive maybe…
the material will be waterproof, just like a waterproof jacket is, just like waterproof boots are. Perhaps you should look at wearing a kayaking drysuit and they are not immune to leaks through the bits your body has to go through!
the water is running down your legs, wear over trousers and you wont have a problem (not so much anyway). Nothing wrong with the product or the manufacturers description just the application.