Just in time for triathlon season and the weekend before the extremely popular NYC Triathlon, here's a chance to practice open water swimming and race transitions. This fun and challenging multi-sport event combines a 1.5-km swim in the Hudson River and a flat, fast, scenic 5-km run in Hudson River Park and Riverside Park. Don't run? Check out the swim-only Tune Up on the same day or help out as a volunteer. Everyone is invited to an informal, pay-as-you-go meal afterward at the 70th Street Pier Plaza.