The Tideline features a 5mm neoprene upper, heavy-duty zipper, and gusseted zipper opening which helps to reduce water exchange. The thick rubber outsole features a proprietary Stohlquist tread pattern for outstanding traction.The ergonomic shape, which echoes the natural shape of the foot, allows for the best possible fit and comfort in a paddling boot. The Ergo® shape also helps to increase the overall warmth of the boot, by contouring the foot and minimizing water pockets.