Quarter Tonner

A small offshore racing yacht built to a quarter-ton rating under the International Offshore Rule, roughly 6 to 8.5 m on deck, that contested the Quarter Ton Cup from 1967. The ton in the name is the old rating unit, not weight; the IOR grouped level-rating classes as One, Half, Three-Quarter, and Quarter Ton. The class drove 1970s innovation in light planing hulls. Many original boats have been restored to race a revived Quarter Ton Cup under a fixed rating cap rather than the obsolete IOR.