The International Marblehead is a class of radio controlled sailing yacht used for competitive racing.
It is a measurement controlled class administered by the International Radio Sailing Association.
As a designated International IRSA class it is entitled to hold World Championships officially recognised by the International Sailing Federation.
A Marblehead has a maximum length of 1290 mm and a maximum draught of ca 700 mm, but no minimum displacement.
Up to six rigs are allowed, the tallest being about 2200 mm.