September 22, 2009

The equinox and the compass

(Enjoy a new Mainly About Boats column here every Monday, Wednesday, and Friday.)

IT’S THE EQUINOX TODAY, one of those gorgeous, calm, sunny days that Puget Sound so often enjoys in September, and I’m thinking of a warm grassy slope on Whidbey Island.

For several years we lived on the island, which lies at the end of the 80-mile long Strait of Juan de Fuca, the restless marine highway that leads directly to the open Pacific Ocean.

Because the strait runs due west from Whidbey Island, the sun sets on the sea horizon on the days of the equinox.

So, in the early evening we would make ourselves comfortable on that warm grassy slope, with a blanket, a bottle of wine, some picnic treats, and my hand bearing compass. And we’d watch the sun.

As you know, it’s only on the day of the equinox that the sun actually sets in the true west. All summer, it’s been setting to the north of west, and all winter it will be setting to the south of west, but on the actual day of the equinox it sets plumb due west. And thus you can test the accuracy of your hand bearing compass.

Our ritual was to start watching when the sun’s lower limb kissed the sea horizon. I took its bearing with the compass when only half the flaming red disk was left showing. The bearing was never 270 degrees, of course, because of magnetic variation. The variation was about 20 degrees east in Oak Harbor at that time, and, as they teach the neophytes in navigation kindergarten, “variation east, magnetic least.” So I subtracted 20 from 270 and got 250 degrees magnetic, which, lo and behold, it always was.

And then, with renewed confidence in my little hand bearing compass, I would go sailing and point it at ships on a collision course, and use it to check the main steering compass, and take beam bearings to make sure the anchor wasn’t dragging.

I don’t live in Oak Harbor any longer, but they tell me that if you sit on that beautiful grassy slope at West Beach, the sun still goes down in exactly the same place on exactly the same date. Just plain habit, I guess.

Today’s Thought
I have a horror of sunsets, they’re so romantic, so operatic.
— Marcel Proust

A little boy and girl came across a high fence surrounding a nudist colony. The girl peeked through a knothole.
“What are dey, den?” asked the boy. “Men or women?”
“Dunno,” said the little girl. “Dey hasn’t got deir clothes on.”

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