San Diego Surf Ladies
Located at Steamer Lane, Santa Cruz, CA, the event is the longest-running longboard contest in existence, in addition to being one of the largest. It's also a benefit for several local charities, including the Junior Lifeguard Program, Ride-A-Wave, Jacob's Heart Children's Cancer Association and the Santa Cruz Surfing Museum.
More info: http://www.surfclubs.org/memorial-day-classic.html
San Diego Surf Ladies is a 501(c)4 registered nonprofit.