Mari-Cha IV is a schooner superyacht, built for American billionaire Robert Miller with the goal of winning sailing records. The designers were Philippe Briand,[1][2] Greg Elliott[3][2] and Clay Oliver.[2] The yacht has a waterline length of 40.2 m, a width of 9.6 m, and a displacement of 50 t. It was equipped with a canting keel, with a 10 t keel bulb, which is able to exert a much larger righting moment than a conventional one.[4]
In 2015 the yacht was renamed Samurai and converted to a fast luxury cruiser. The canting keel was replaced by a simpler retracting keel, and the ship was given a new cabin and interior.[5][6]