In the late 1800s, a variety of fog signals resounded along the shore, echoing in the neighborhoods and nearby waters of the Bay. Bells, whistles, gongs, cannons, horns, sirens, and even voices were all uses to guide boats to safety.
Imagine hearing this cannon boom every half-hour as it once did at Point Bonita - near the entrance to the Golden Gate Bay - in the 1850s, whenever fog covered the Bay! Pity its lone keeper, who, having to fire it around the clock until the fog lifted, lamented, "I have been up three days and nights, had only two hours' rest. I'm nearly used up." Bells and horns soon proved easier, cheaper, and more effective as fog warnings.
In an age before radar and marine radios, San Francisco's 19th century Italian fishermen sang as they worked the fog-shrouded waters outside the Golden Gate. Lusty renditions of popular operas and folk songs from the old country communicated the identity and location of the singer to any other boats fishing in the area.
The 1,600-pound bell above you was once mounted on top of the shed on Pier 1, across from the Embarcadero Center. In times of fog, it was rung every five minutes. The wooden sounding board is a replica of the original.
"The danger lay in the heavy fog which blanketed the Bay, and of which, as a landsman, I had little apprehension. From out of the fog came the mournful tolling of a bell, and I could see the pilot turning the wheel with great rapidity. The bell, which had seemed straight ahead, was now sounding from the side. Our own whistle was blowing hoarsely, and from time to time the sound of other whistles came to us from out of the fog." --from The Sea Wolf, 1904
(Click the image to view a smaller version.)