During the 1930's J-class yachts were built to race in the America's Cup. Only 10 were ever built, or converted to J-class, as they were extremely expensive to build and maintain, especially in the post war years after the Cup resumed in 1958. They were replaced by the 12-metre class yachts.

The J designation refers to the class of yacht defined by its sail area, displacement, length, and mast height, formally defined in the Universal Rule. When designing a J-class yacht builders would have to decide which characteristics to maximize to build the ideal yacht.

America's Cup

All three America's Cup races featuring J-class boats were won by the United States. In 1930 the Enterprise defeated the Shamrock V of Ireland. In 1934 the Rainbow defeated the Endeavour of Britain. And in 1937, the peak of J-class yacht racing, the Ranger defeated the Endeavour II of Britain.

Specifications

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Only 10 yachts were ever built or converted to conform to J-class specifications:

Name	Year	LOA	LWL	Beam	Draft	Disp.	Built
Enterprise	1930	120 ft 9 in	80 ft	23 ft	14 ft 6 in	128 tons
Whirlwind	1930	139 ft	86 ft	21 ft 9 in	15 ft 6 in
Yankee	1930	126 ft	83 ft	22 ft 6 in	14 ft 6 in	148 tons
Weetamoe	1930	125 ft 9 in	83 ft	20 ft	15 ft
Shamrock V	1930	119 ft 1 in	81 ft 1 in	20 ft	14 ft 9 in	134 tons
Velsheda	1933	127 ft 6 in	83 ft	21 ft 6 in	15 ft
Endeavour	1934	129 ft 6 in	83 ft 6 in	22 ft	14 ft 9 in	143 tons
Rainbow	1934	127 ft 6 in	82 ft	21 ft	15 ft	141 tons
Ranger	1937	135 ft	87 ft	21 ft	15 ft	166 tons
Endeavour II	1937	135 ft 6 in	87 ft	21 ft 6 in	15 ft	162 tons

• Disp: Displacement
• LOA: Length overall
• LWA: Length at water line

External links

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• J Class Association

Keelboats | America's Cup participants | Ship classes

J-Klasse (Segeln) | Klasa J