Why do i have register to get the free boat plans? basically i would like to know my visitors and have the opportunity to get in contact with you.. Free pontoon boat plans. well look what we have cooking here: free plans to make your own pontoon boat! length: 12′ (3.7 m). Trimaran designs hank brooks’ f-31 at musgrave landing, canada. previously available trimaran designs for home builders: f-85sr – f-32sr.