Hundreds of athletes are expected to "Escape from the Rock" on Saturday during the annual duathlon and swim event at San Francisco's Alcatraz Island.
Now in its 39th year, the "Escape the Rock" event begins on the island, where participants will swim 1.5 miles to the shore at Aquatic Park.
Afterward, those participating in the duathlon will take an additional 7-mile run to Fort Point, passing through some of the city's most scenic locations.
The more than 300 participants already registered are being asked to arrive at the Maritime Museum between 6:45-7:45 a.m. to check in. Afterward, they'll leave from Pier 41 via ferry to Alcatraz.
The swim starts at 9:15 a.m. A swim-only awards ceremony will then be held at 11 a.m., followed by the announcement of the duathlon winners at noon.