Yacht design was originally carried out by the shipwright or boatbuilder commissioned to build the yacht, and quite often to the shape agreed of a half model produced by the builder. A successful design would be copied and modified so that existing patterns could be used. In the late 19th century the advent of rating rules influenced the previous, more traditional shapes, so that more extreme types, such as the skimming dish, were developed to try and beat these rules.
The introduction of steam propulsion led to many large iron auxiliary and full-powered steam yachts being built. However, it was not until about 1870 that yacht design began as a separate profession, though most yacht designers retained strong links with building yards. Each developed his own style and yachts could be recognized as being from a particular designer.
In the 1930s the increase in ocean racing (see yachting: sail) and dinghy racing led to an increasing number of designers producing race-winning designs so that design offices expanded. After the Second World War (1939–45) yacht design was generally low key with small simple yachts, but by the 1950s the introduction of GRP provided a boost, and the spread of various forms of ocean racing provided battlegrounds for designers. Many of the successful ones from this period later became involved in the design of larger and larger yachts where a lot of the detail work again devolved upon the building yard.
Following modern shipbuilding practice, the modern yacht designer will work closely with a stylist and interior designer, as yachts become ever more sophisticated. However, he will still be responsible for the yacht's fitness for its purpose, and for performance, stability, structural integrity, and safety. To establish these he will first of all normally produce, for a sailing yacht, a preliminary general arrangement and a sail plan for the owner's approval and as a basis for a written specification with which to obtain building estimates. A lines plan is then produced, so that stability and performance checks can be made together with detailed weight estimates, and a construction plan, including decks and the scantling section. These, together with other structural drawings such as bulkheads, tanks, machinery seatings, stern gear, and rudder arrangements, may all need approval by a classification society. At this stage it is likely that the builder and the interior designer will become involved with the development of all the systems and the detail of the interior. Other specialists may also be brought in to design the spars, rigging, sails, and deck gear. There may be as many as 100 drawings for a 10-metre (32-ft) yacht or 400 for a 20-metre (65-ft) yacht.
From the inception of yachting, yachtbuilding followed the traditional methods used to build small commercial wooden vessels such as barges and smacks, with one of the main tools being the adze. The wood keel, of oak, elm, pitch pine, or other local timber, was laid on the slipway or on building blocks, and the wooden stem, sternpost, and stern frame bolted into place. The various frames (or ribs) were sawn to shape and erected in their respective positions along both sides of the keel from stem to stern, the lower ends of each pair being fastened to floor frames which were commonly oak crooks laid athwart the top of the keel. An inner keel, or keelson, was sometimes bolted on to the tops of the floor frames and running from the inside of the stem to the sternpost. Beam shelves, running from bow to stern and fastened to the inside of the head of every frame, carried the outboard ends of the deck beams which in turn were fastened to the shelves, often with a half-dovetail joint. Openings in the deck for hatches or skylights were joined by carlings to which the coamings were fastened. At all junctions beneath the deck where the racking strains of hard sailing in heavy seas were greatest, oak crooks or wrought iron knees were bolted to give more rigidity, hanging knees being vertical and lodging knees horizontal.
Subjects: Maritime History.