I need to cover the cost of site hosting at least or this site may disappear! —–my thanks to many people for their input and. A pt boat (short for patrol torpedo boat) was a torpedo-armed fast attack craft used by the united states navy in world war ii. it was small, fast, and inexpensive to. Free boat & ship plans boats, ships & anything that floats. this section is dedicated to free boat plans. each plan is available as a zipped file and will either.