aqua-bound challenge 85 2-piece stand-up paddle aqua bound the challenge sup has a lightweight, all-carbon shaft with a 10 bend to provide low swing weight and a slight shaft flex for a very comfortable performance. its epx engineered polymer blade has enhanced stiffness and strength thanks to its carbon-fiber reinforcement. the blade has an aggressive dihedral down its spine for a smooth, forgiving forward stroke. the challenges overall black color makes it an ideal color match for virtually every sup board.