Astral Hiyak Outdoor Boots for Water and Boat Designed for all kinds of kayaking, rafting, and river SUP G.S.S. (super-sticky") highest friction rubber 3.5mm outsole with siping and drain holes at the toe and heel. Non-marking. Removable, 7mm thick 45C closed cell EVA foam midsole 1000D Cordura Nylon with 1060D ballistic nylon reinforcement rand High top padded ankle protection with semi-rigid heel cup