The raingutter regatta is a racing event for Cub Scouts in the Boy Scouts of America that is the sailboat equivalent of the pinewood derby. The sailboat kit consists of a seven-inch (178 mm) long balsa wood hull, a 6-1/2 inch mast, plastic sail, plastic rudder, and metal keel. Within the basic design rules, Scouts are free to paint and decorate their sailboats as they choose. Modifications for speed include the placement of the keel and rudder and the size, shape and location of the sail. A catamaran is an exceptionally fast design, although this modification is not allowed in all races.