 He assisted W. Starling Burgess with the design of the J-Class "Ranger", which won the America's Cup in 1937, defeating the Royal Yacht Squadron's "Endeavour II" in four races.He was the original designer of six out of seven successful 12 Metre defenders of the America's Cup between 1958 and 1980, with the exception of "Weatherly" in 1962.Other than "Ranger", the most remarkable of his defenders was the "Intrepid".