In my summer community we confer a mock trophy on a hapless boater every season, called the Bent Prop Award. It’s for minor nautical mishaps: boats drifting off their moorings or running out of gas, or skippers getting lost in the winding creeks after a night of revelry. But we can have 10-foot tides in the Ipswich River estuary, so the most reliable summer blunder around here is running aground.
The planet is spinning in space at nearly 1,000 miles per hour, and flying though its orbit around the sun at an unthinkable 67,000 mph. But we don’t feel it; we need the tides to remind us that we are moving at all. The regular flood and ebb and flood of the oceans is caused, of course, by the gravitational pull of the moon, which is strongest when we rotate closest to it. The force is powerful enough to suck the earth’s oceans into a bulging blue muscle on that side of the earth, draining bays and estuaries elsewhere — and trapping boaters for as much as six hours upon unfamiliar sandbars.
I’ve nearly been there myself. One hot July day, my husband and I took our guests through the oxbows of Fox Creek. We thought we had plenty of room to maneuver, because it was an especially high tide that day, one of two times a month when the moon, earth, and sun all line up in what is called syzygy (which is also an excellent Scrabble word). What we didn’t realize is that an especially high tide also means an especially low one. Everything was accelerated, and the muddy bottom scraped the propeller of our tin boat long before we expected it. We all had to get out and tug the vessel through the narrow channels, slapping at flies and singing like a group of Russians hauling a barge along the banks of the Volga.
Can there be a better metaphor for time, or for constancy, or for power? The tides ply their regular, implacable motions without cease, as if a great planetary breath is rising and falling. They are indifferent to the plovers playing tag with the waves, the striped bass struggling against the current, or the marsh grasses growing tall and green, or yellowing with autumn seed, or collapsing under the weight of the first snow.
Neither do the tides care about the petty concerns of man; the upheavals of families or great institutions or governments are nothing compared to the eternal movement of the seas. We can learn a lot from this: that world events are cyclical, that there are larger forces working upon us than we realize. These days, many of us feel we are headed for the rocks. We may be swamped by feelings of despair. That’s when it helps to remember that, eventually, the tide will turn, and we can steer ourselves to calmer waters. Learning to live in harmony with this will help us avoid the shallows.
But what I love most about our swinging tides is the ever-changing vistas they provide. Because of fluctuations in the moon’s orbit, the tides move around the clock roughly 50 minutes later each day, so a creek deep enough to dive into at noon on Monday will be pure mud at noon on Saturday. The sunset may reflect pinkly in the full waters or cast long shadows upon dry banks. Nothing looks the same way twice.
Moving 10 feet of water in six hours means a rate of 20 inches an hour, or an inch every three minutes. Thin fingers of salt water creep up the beach, filling creases in the sand. If you are patient, you can stand there and watch the earth turn.Renée Loth's column appears regularly in the Globe.