The park includes an extremely popular, but cold, area to do recreational and competitive open water swimming.
In front of the Maritime Museum is a man-made lagoon on the site of the former Black Point Cove. To the west is the horseshoe shaped Municipal Pier. The lagoon is fronted by a sandy beach and a stepped concrete seawall. To the south is a grassy area known as Victorian Park which contains the Hyde Street cable car turnaround. Hyde Street Pier, though part of the San Francisco Maritime National Historical Park, is not part of Aquatic Park Historic District. Every single day of the year, members of the Dolphin Club and South End Rowing Club and their visitors swim in this world-renowned lagoon and well-kept beach.