Abstract: A pontoon (20) for a boat (22) includes a base member (24) and a closure member (26) which are attached to form a U-shaped performance structure and a cylindrical support structure. A foam (74) filled nose cone (29) is connected to front ends (36,46) of the base member (24) and closure member (26), and an end cap (28) is connected to the back ends (38,48) thereof to form an air tight chamber (66) in the support structure. The pontoon (20) is connected to a deck (30) of the boat (22), so that the pontoon (20) contacts the deck (30) along the entire length of the pontoon (20).