In September, 1933, the Royal Yacht Squadron offered a challenge for the next America's Cup. T.O.M. Sopwith, renowned aircraft designer, wasted no time in using some of his best people to develop Endeavour . The results of their efforts was a J-Boat that was quite technologically advanced for her time. Endeavour was more technologically advanced than the defender, Rainbow, and was obviously the faster of the two. Unfortunately for the British, that was not enough to take the America's Cup away from the Americans. In one of the closest America's Cup races in history, Rainbow defeated Endeavour by taking advantage of Endeavour 's amateur crew and out-thinking her captain.
Endeavour was designed and built by Camper & Nicholson to the order of Mr. T.O.M. Sopwith for his first America's Cup Challenge in September 1934. Displacing 143 tons and measuring 129 feet in length with a 22 foot beam, she carried 7,560 square feet of sail and was considered the best 'J' boat of her day. Despite this, she narrowly failed to wrest the 'Auld Mug' from the American defender Rainbow but nevertheless went on to enjoy a highly successful career and is one of the only three J-class yachts which have survived to ornament the contemporary racing scene.
Built by Herreshoff Mfg. Co., Bristol, R.I. for the Vanderbuilt Syndicate, Rainbow was narrowly selected by the New York Yacht Club to defend the America's Cup. Designed by W.S. Burgess with an overall length of 128.56 feet, beam 20.4 feet, and draft of 14.95 feet, Rainbow was steadily improved by adding ballast and setting larger sails. After losing the first two races to Endeavor, Rainbow won the closest Cup match ever, amidst protests and errors on both sides. Rainbow was the fifteenth defender of the America's Cup.