Yarrawonga Plastics - Pontoons Build your own Pontoon/Barbie Party Boat. As long as you want and as wide as you need it, your imagination is endless. A floating deck, do it yourself (EASY). Modular Pontoons are used for both work and recreational vessels for inland waterways. They are a low cost option to building your own Fun boat. A smaller pontoon is also available, used widely for Jetty's and Dam Pumps.