http://www.coliesail.com/schedules.html = Most useful class calendars

lhttp://www.ussailing.org/Championships/ = US Sailing

http://www.usoda.org/index.cfm?id=115701&fuseaction=browse&pageid=35 = Opti Class

http://www.laser.org/m/_general/events.asp = Laser Class

http://www.club420.org/calendar.htm = 420 Class