Endeavour II, America's Cup challAmerica's Cup challenger prepares for Atlantic crossing. In preparation for her Atlantic voyage to challenge for the America's cup, Endeavour II, Mr T. O. M. Sopwith's yacht, is being fitted with a short mizzen mast and short main mast. Photo shows: Endeavour II being prepared for her Atlantic crossing in dock at Gosport, Hampshire. 28 April 1937