The La Jolla Rough Water Swim has been running continuously since 1916 — making it the oldest open water swimming event in the United States. September 13 at La Jolla Cove. From the 1-mile Gatorman to the 3-mile championship course, the cove is wall-to-wall swimmers and spectators from dawn. Even as a spectator, watching a thousand swimmers enter the Pacific at once is something you don't forget. Registration at ljroughwater.com.