The Alcatraz Sharkfest Swim is a 1.5-mile open-water race across San Francisco Bay, from Alcatraz Island to Aquatic Park. The water temperature is typically 60-62°F, presenting a challenge beyond the distance, as swimmers contend with cold bay water, chop, and current. This event is part of the Sharkfest Swim Series, organized by Enviro-Sports, with the schedule determined by tides instead of a set start time.
The swim requires more preparation than a pool race; swimmers are advised to aim left to prevent the current from pushing them beyond the Aquatic Park entrance. A KQED writer who participated described a one-hour swim involving ingested bay water and contact with other participants, conveying the crowded, competitive atmosphere. The Alcatraz race initiated the series in the early 1990s. Following a significant interval before the subsequent Sharkfest event, the series expanded to include multiple point-to-point swims, such as Golden Gate, Lake Tahoe, and San Diego, with the San Diego race functioning as the series championship.