A measure of the standard of a yacht’s construction as certified by one of the ‘classification societies’ such as the American Bureau of Shipping, Lloyds Register, Bureau Veritas (France), or the like. In Britain, a boat built to Lloyds standards and under their supervision may, for example, be classed ‘100 A1’, but she will lose that rating if she is not inspected by Lloyds at specified intervals. At such regular surveys Lloyds will specify what corrective work must be done to enable her to remain ‘in class’.