Lofting is a drafting technique (sometimes using mathematical tables) whereby curved lines are generated, to be used in plans for streamlined objects such as aircraft and boats.
Lofting is an art and a science. The designer’s boat plans include offset tables and very accurate drawings which must be translated into full-scale templates.
The first step is to lay out the grid, mark the Base Line along the length of the paper or plywood sheet. Then nail Battens every 12 inches (or more in some cases) where the station lines are to be set as a mark for the perpendicular line, which is marked with a T-square. The previous steps are followed in turn by marking the Top Line and the Water Line.
The Battens in this case are 2×4’s are mapped out on the build deck, more accurately called a lofting platform, spaced 2 ft apart to set up a guide for standing up the hull frames.