Welcome to absolutely free plans, in this section you will find free boat building plans including accessories and construction techniques. free plans have a tendency. How to build a paddlewheel riverboat party barge drawings instructions, plans for homemade sternwheel boat, the paddlewheel diy boat kits. A steamboat is a boat that is propelled primarily by steam power, typically driving propellers or paddlewheels. steamboats sometimes use the prefix designation ss, s.