Foam surfboards are constructed using similar techniques as rigid surfboards. It’s the materials that change. The foam boards are covered with non-slip foam on the deck and slick on the hull. The slick is made of HDPE (High Density Polyethylene): HDPE is a type of plastic which provides excellent rigidity and impact resistance while guaranteeing good gliding qualities to the board. The core of the board is constructed with a block of polystyrene