Located on the infamous prison island of the same name on San Francisco Bay, Alcatraz Light serves to mark the line between the east and west San Francisco Bay traffic lanes, and also to announce the presence of the island itself.
The stone and mortar structure towers 84 feet above the ground, while the 200,000 candlepower focal beam shines exactly 214 feet above the waters surface. The keepers house, an old fog tower and the light itself are what remain today, and all are part of the Golden Gate National Recreational Area. The buildings are viewable from the water, or as part of a visit to the island, which requires a ferry trip from Fishermans Wharf in San Francisco.
Alcatraz Light is the first and oldest lighthouse in California. The foundation of the stone and concrete lighthouse was first laid in 1852, but delays in funding and the arrival of the lighthouses lens delayed the lights first operation until 1854. A firm from Baltimore, MD oversaw the construction with the arrival of the construction barge Oriole in 1853.
In 1909, the original lighthouse was razed to make way for a prison and a new light was constructed next to the main cell house. Construction was complete by the end of 1909 and the new light was lit on December 1, 1909. The lighthouse was automated in November 1963 after the federal government decided to close the prison due to budget issues and cost overruns.
Use NOAA Chart 18650.
Alcatraz Lights rotating beacon flashes white every five seconds, and a horn on the north end of the island will sound during periods of fog (which can be quite often over the cool San Francisco Bay waters).
A green and red bell buoy marks the northern end of the island, and rock shoals protrude from the island to the west. There are no public docks on the island the pier facilities are reserved for ferryboats only. Beware of very strong tidal currents in the area during both ebb and flood tides.
Alcatraz Island is open for tours, and ferryboats leave Fishermans Wharf on an hourly schedule. The lighthouse and keepers house are not open for tours, however.