In an effort to respond to noise complaints while maintaining safety of the coast of San Mateo County, the U.S. Coast Guard is experimenting with sound plugs on the foghorn at the entrance of Pillar Point Harbor.
The Coast Guard placed three plugs, or baffles, on the foghorn on May 24. They will remain in place through July. Based on feedback, the Coast Guard will decide whether to keep the plugs permanently, Chief Warrant Officer Mickey T. Price wrote in an email to the Review.
The signal emits sound in 360 degrees. Each of its eight ports emit sound at 45-degree segments. The three plugs cover 135 degrees and should block some sound headed north, northeast and east, Price said.
The Coast Guard has been researching the foghorn for years, most recently since November 2020. It received more than 80 responses from the local community in December after asking mariners and residents about the sound.
The plugs also serve another purpose. They boost the sound in the opposite direction toward the ocean, which might actually improve navigational safety, according to Price.
“We are interested to see if there might be any slight changes that may best serve navigational safety (which is the purpose of the signal), while at the same time slightly lessen perceived negative impacts which can be interpreted as ‘noise,’ and still maintain the aesthetic of the signal which is dear to many in the community,” Price said.