Archive for January 23rd, 2013

Jan 23 2013

Fog horns on a snowy night

Published by under Cape Cod,Cotuit,General

When it snows in Cotuit something happens to the acoustics and I can stand outside in my driveway, snow flakes falling on my hair, and hear, every thirty seconds. the plaintive lonely hoot of a fog horn somewhere off to the south across the waters of Vineyard Sound.

I’ve heard it every winter I’ve lived in Cotuit. It is a remarkably lonely sound — commonplace for a San Franciscan accustomed to that city’s orchestra of fog horns — but rare to hear here in Cotuit, only possible when the horns are activated during low visibility and then only heard when the wind is still and the conditions are just right.

I used to assume there was only one horn and that it was in Woods Hole at Nobska Point, but two nights ago, as three inches of snow fell on Cotuit, I heard not one, but two horns, almost simultaneously but one fainter and a bit behind the other. So I turned to the navigational chart of Nantucket Sound and realized the louder horn, the one I hear most often, is from the lighthouse on West Chop on Martha’s Vineyard, at the promontory north of the Mink Meadows golf course. The second horn is most likely Nobska, site of a grand classic lighthouse that was the highpoint of my occasional bicycle ride around the western half of the Cape and where the famous Falmouth Road Race passes by every summer.

Fog horns can be deceiving, tricky things to pinpoint in the murk because of the way water droplets in the air bend the sound and distort their apparent source. While my theory of why the Vineyard horns are only audible here in Cotuit (about ten miles as the crow flies) during snow storms, I think it less about the snow in the sky than the calm waters of the sound. Sound travels very well at night over calm water — ask any teenager trying to sneak across the channel to Sampson’s Island for a midnight party how quickly the locals flip on their bedside lights and call the police — and indeed I can only hear the signals when there is no wind at all. If you’re interested in geeking out on the physics involved, one John Tyndall wrote a paper on the effects of snow and fog on the audible distances of fog horns in 1875.

Navigating in pea-soup fog or snow by sound is amazingly difficult, but the rules of the road demand that any vessel obscured in the murk must blow a horn or ring a bell or blow a whistle on a regular basis. When I was a deckhand on a ferry running between Hyannis and Nantucket foggy days (generally in the late spring) were very tense times, with the captain sitting beside the helmsman, face stuck in the rubber eyepiece of the big Raytheon radar set, pulling the horn’s lanyard with a bowel-rumbling honk every minute, and me usually stuck in the prow, peering into the wet cotton, looking out for errant sailors and fishermen we might run over. I was supposed to point at whatever object I saw and raise and lower my hand slowly, turning back to the pilothouse to confirm that the helmsman or Captain had also seen it. Given my coke bottle thick glasses, I generally was the¬†last person to spot things like 100-foot long draggers or our 150-foot long sister ship steam on a parallel course in the opposite direction. I’d wipe my glasses, squint, see something, point and then turn only to be given the middle finger by Captain Ellis who saw the boat a good ten minutes earlier on the radar.

I’d rather stay at the mooring and rebuild a winch than try to dead reckon my way through the fog.

Anyway, hearing fog horns on Martha’s Vineyard during snow storms is another on of those ¬†Cotuit “things” like high tide on full moons at noon and midnight.

 

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