Lofting is a term used in wooden boat building. A boat design starts with a complicated drawing that lists dimensions and other pertinent information. In an effort to ensure the finished boat maintains its lines, including graduated curves in the hull, builders require the initial design drawings in full, true scale. By sketching out the design plans in full scale, the builder can better see exact sizes and assembly requirements prior to cutting individual wood components. This process of converting scaled down drawings to full size templates is what is known as lofting.
As a drafting technique, lofting is considered an old fashioned method which requires far more steps than necessary, especially in commercial boat building. Shipwrights must take a lines plan, the initial design drawing, and convert it to a full sized plan using complicated mathematical computations and formulas. With the help of modern technology, lofting is no longer a necessity. Computer-Aided Design (CAD) long ago replaced lofting as the preferred method of drafting boat blueprints. CAD designs provide exact measurements based on any scale, with just the click of a mouse.
Hobby boat builders, however, often enjoy the process of lofting boat lines rather than purchasing prefabricated blueprints. In terms of ship construction, hobbyists frequently prefer the time and attention to detail required when using this particular method of drafting. Detail drafting work may be especially attractive to hobbyists for whom the woodworking aspect of boat building is the most enjoyable task. Lofting allows them to visualize each piece of wood before they begin cutting and shaping it, imagining where each piece will join into the whole.
Historically, the process of lofting began sometime between the Medieval ages and the Industrial Revolution. Previous to this, master shipwrights maintained a secretive environment around building methods to insulate their trade — the first treatise on boat building was not published until as late as 1436. As naval architecture advanced into a recognized profession, draftsmen became an integral part of boat building and publications outlining various maritime methodologies, including lofting, becoming more widely available.
Modern commercial boat building mainly uses prefabricated steel construction for hulls and keels, eliminating the need for wood plan designs and subsequently, the need for lines plans. Private boats, yachts, and other small craft designs, however, still feature many wood and composite building materials. As such, the process of lofting remains a subject of interest for small vessel builders, especially those small scale shipwrights for whom custom wood boats are a specialty. Numerous books and other publications detailing this drafting process are available worldwide.