The Nantucket One Design Fleet is comprised of the following classes: Alerions, IODs, Indians, Rhodes 19, Marshall Cats, Club 420, Rainbow (Beetle Cat), 420's and Optimists. In order to sail in scheduled races, skippers must be a member of the Nantucket Yacht Club or officially approved by the Nantucket Yacht Club as a racing guest. Races are held every Saturday during the months of July and August, except for IODs which race on Sundays.