Build a small sailboat free plans . these plans are for a small 15 foot knockabout sailboat. i like these plans for their ease. building a smaller boat is a lot more. We have power boat building designs of all types such as power cats, cruisers, and more. view jon boat deck plans & boat cabin plans for more details.. Free motorboat plans for the backyard home builder, build your own speed boat, cabin cruiser, runabout or utility boat using these simple plywood designs..