It was a dark and foggy night when I heard the low blare of a horn in the distance. Do the big ships in the Port of Vancouver still need foghorns to get around in the fog?
The first automatic, steam-powered foghorn was installed in 1859, on the other side of Canada, on Partridge Island, New Brunswick. Robert Foulis, a multi-talented, transplanted Scot working as a deputy land surveyor in Saint John, developed the device after noticing, while walking home one foggy evening, that the lowest notes of the song his daughter was playing on the piano sounded the most clear. Despite this storybook opening, Foulis did not patent his idea and ended up broke—even with the worldwide adoption of foghorns.
Lower notes have longer wavelengths, which allow them to step around obstacles more easily than higher notes. The water droplets of the fog do not diffuse lower notes as easily as higher ones, so you can hear them over greater distances.
Foulis' invention blew its own horn until 1998, when it was shut off. None of the ships in the harbour complained, because nowadays ships generally rely on fancier, electronic navigational equipment; however, many nostalgic residents did.
Come Blow Your Horn
So, the horns you hear are coming from the ships, warning each other as they pass through the First Narrows, under the Lions' Gate Bridge. Some of the cruise ships even have horns that can play tunes. And in St. John's Newfoundland, ships have even performed symphonic music with their horns.
If you know more about ship protocol, please share. If you have experienced sounds in the fog, that would be interesting to know about too.