Model yachting is the pastime of building and racing model yachts. It has always been customary for ship-builders to make a miniature model of the vessel under construction, which is in every respect a copy of the original on a small scale, whether steamship or sailing ship. There are fine collections to be seen at both general interest museums such as the Victoria and Albert Museum in London and at many specialized maritime museums worldwide. Many of these models are of exquisite workmanship, every rope, pulley or portion of the engine being faithfully reproduced. In the case of sailing yachts, these models were often pitted against each other on small bodies of water, and hence arose the modern pastime. It was soon seen that elaborate fittings and complicated rigging were a detriment to rapid handling, and that, on account of the comparatively stronger winds in which models were sailed, they needed a greater draught. For these reasons modern model yachts, which usually have fin keels, are of about 15% or 20% deeper draught than full-sized vessels, while rigging and fittings have been reduced to absolute simplicity. This applies to models built for racing and not to elaborate copies of steamers and ships, made only for show or for " toy cruising."
Traditional models are constructed of some light, seasoned wood, such as pine, preferably white pine, white cedar or mahogany free from knots. The hull may either be hollowed out of a solid block of wood, or cut from layers of planks in the so-called bread-and-butter style, or planked over a frame of keel and cross-sections. The first two methods are used in constructing dugout models. Hollowing out from the solid block entails a great deal of labor and has therefore fallen into disfavor. In the bread-and-butter style a number of planks, which have been shaped to the horizontal sections of the model and from which the middle has been sawn out, are glued together and then cut down to the exact lines of the design, templates being used to test the precision of the curves. In the planked, or built-up model, which is generally chosen by more expert builders, the planks are tacked to the frame, as in the construction of large vessels. Hulls may also be formed from modern plastics, which may be purchased from a manufacturer as termomoldings or fiberglass layups or fabricated by the modeler, by first making a positive model from clay or plaster (or using an existing model's hull) and then creating a negative mold from fiberglass or plaster. Models may be exaggerated cutters, so far as their underbodies are concerned, or, more often, are fitted with fin-keels weighted, after the manner of full-sized yachts. They may have any -rig, but schooner and sloop rigs are most common, the latter being the favorite for racing on account of its simplicity.
This is accomplished by the weighted rudder, which falls over when the vessel heels and tends to counteract the force of the breeze. There are two varieties of the weighted rudder, in the first of which the weight, usually lead, is fixed to the edge of the rudder, while in the second the weight, usually a ball of lead, is made to run on the tiller above the deck, so that it can be placed further forward or aft, according to the force needed to overcome the influence of the wind. The weighted rudder is almost universal in the British Isles. Weights are also incorporated into the other, following methods.
A more accurate method is to use a separate rudder vane; this is made from a plank of light wood such as balsa. The vane is operated in two principal positions, one for upwind sailing, the other for downwind. While some modelers object that the model craft will not be a plausible representation of its full-sized prototype, real long-distance cruising boats are frequently steered with dedicated windvanes of varying complexity (mechanical or electronic), occasionally with a line attached to a sheet, and never using weighted rudders.
With the advent of radio control it has become much more practical to operate motorized craft. While some are powered by water-cooled internal combustion engines and can be very powerful and fast, the noise and fast operation is discouraged in many park settings as too disturbing to patrons, waterfowl and other wildlife. Electric power and low pressure steam engines are popular, with many amateur machinists building engines from casting kits. Specialized regattas for radio-controlled motorized craft are held that include rubber duck herding and the simulated rescue of ships in distress by a team of operators controlling a pair of tugboats.