Welcome to the wharram catamaran forums. whether you’re looking for an answer to a building problem, want practical advice on the sailing of wharram designs or simply. Small ships register pleasure craft small ships register online registration for part iii includes for change of ownership or change of address. Building your own boat with wharram designs is the easiest and most cost effective way to fulfil your sailing dreams. wharram self-build boat plans start from only £100..