Universal Rule

The Universal Rule is the rating formula Nathaniel Herreshoff devised in 1903, expressing a yacht’s rating from a relationship between sailing length, sail area, and displacement. Its letter classes, named down the alphabet by rating, produced the J Class that contested the America’s Cup from 1930 to 1937, the largest single-masted racing yachts ever built. It competed with and was eventually displaced by the International Rule used in Europe, whose Metre classes such as the Eight and Twelve survived longer.