Want to save hundreds of dollars by building your own trailer? are you looking for free trailer plans? do you want to look after & maintain the trailer you already have?. Check out our range of free trailer plans an building instructions. easy to read and understand drawings, sketches and tips to help you build your own trailer, step. Boat plans by mike waller yacht design. quality plans for amateur boatbuilders, monohull and multihull, catamarans, sharpies, skiffs, power catamarans and.