The GGR Supply Non-Skid Tape that is waterproof because of its backing. This high traction anti-slip tape is 32 Mil. 60 Grit Silicon Carbide; surface is similar in feel to 60 grit sandpaper therefore it is not appropriate for bare feet. Also, it is coated with an aggressive acrylic adhesive (better adhesive than synthetic Rubber) that cannot be submerge into the water or applied underwater; when applying the surface needs to be dry and free of any debris so the adhesive bond can form properly. If when apply there is any gap that would allow the water to seep underneath of the tape, water will degrade the adhesive very quick.