This small boat design is for a simple but very practical dinghy, based on a reliable pram built several years ago. purchase your dinghy building plans!. How to build a small sail boat. these plans are for a small sail boat called the biloxi dinghy. former builders claim it’s a great design.s. from the plans:. Boatplans.dk – online free and inexpensive boat plans for canoes, small boats, sail boats, motorboats and powerboats. download boat plans right away. – boatplans.dk.