Sunsets, graded.
Every clear evening the Powder Point Bridge puts on one of two shows, and the tide decides which. High water at sunset turns the bay into a mirror with a plank walkway across it. Low water turns it to bronze: wet flats, standing birds, channels full of sky. Both are worth the walk, but they are different walks. Below, every evening ahead with its sunset time, where on the horizon the sun goes down, and exactly what the tide will be doing under your feet.
Loading the evenings ahead from the tide data…
Sunset from NOAA solar equations for the bridge · Tide from NOAA station 8446166 predictions · Times local
How to read it
A Mirror night means the bay is at or near full at sunset: still water to the horizon, the marsh brimming, the classic photograph. The star marks glass nights, when high water and sunset land within about forty-five minutes of each other. Brimming means the bay is mostly full and moving, flood or ebb, with current seams catching the light. Half tide is the working bay: channels, exposed edges, water visibly going somewhere. Bronze flats means the tide is out and the show is the sand itself, acres of it, wet and lit; walk it with the flats page in hand.
The sun's setting point swings farther through the year than most people expect: from about 238 degrees, over Kingston Bay to the southwest, at the winter solstice, out to about 303 degrees, up past the marshes to the northwest, at the summer solstice. In summer it sets over the Back River marshes; in winter it sets down the bay. The bridge faces both.
This page computes itself from the same NOAA tide predictions that drive the tide chart and the flats page, so it always shows as far ahead as the loaded data reaches, and refreshes when the tide data does each month.
The tide chart
This month's highs and lows, king tides, and moon phases for Duxbury Bay.
Walk the flats
When the bay empties and how long the sand stays open, day by day.
The Powder Point Bridge
A history of the Long Bridge, from a draw for tall vessels to the current battle over concrete.