Here is a wonderful activity to keep Chappaquiddickers from going stir crazy this winter: every other Thursday, from 6:30 to 9:30 p.m. bring your art supplies and join artist Elizabeth Whelan for free evenings of drawing and painting at the Chappaquiddick Community Center. For each session Elizabeth will set up two different still-life arrangements from which to work — one simple and one complex. Come and sketch or paint or bring your own project to work on. This is not a class, you can do your own thing. However, Elizabeth will give input to anyone who wants help. Pencils, chalk, pastel, charcoal, and water-based media welcome. If using oils, please use Gamsol odorless thinner only. Meeting dates are Thursdays as follows: Jan. 25, Feb. 8 and 22, March 8 and 22, April 5 and 19.

Potluck dinners at the community center continue on the first and third Wednesday of each month from 6 to 8 p.m. Sign up to host the dinner by calling Lynn at 508-627-8222 or by putting your name in the date book next time you are at the CCC. Please bring a dish to serve six. It can be an entrée, side or dessert.

When Bill Austin started working at Vineyard Land Surveying many decades ago, the first thing he asked me was, ”What is the tide range in Edgartown Harbor?”

I learned over the years that he loves a trick question. He already knew what the Coast and Geodetic Survey folks had figured out. I said that it is three feet. He was disappointed that I could be so wrong. The U.S. government had figured it out at just over one and a half feet. But of course, they were taking the difference between the average high tide and average low tide levels measured over the course of a decade. And I agree with those numbers. They are important when designing piers or bulkheads or determining where to draw the shoreline on a property survey. But what I witnessed in person while operating the ferry on a daily basis was mostly a rise and fall with each tide of about three feet. It’s knowing what we had to deal with during a couple of tide cycles that made it possible for us to tell loaded concrete mixers and dump trucks when the tide would be high enough for them to make multiple trips during the day.

If you look carefully at the tide tables you will see that sometimes the daily difference between high and low tide is greater than usual and sometimes a whole lot less. It is all determined by the phase of the moon and its proximity to the earth. Since the moon’s position is very predictable, the times and heights of the tides are also very predictable. The wild card in all of this is the wind. Its direction and strength have an enormous effect on tide levels.

On Jan. 4, the wind blew steadily from the northeast at 40 miles per hour, gusting occasionally over 60 mph. That caused an abnormally high tide which inundated the Edgartown waterfront. The Chappy ferry is encircled by a six-inch-high rubber bumper at the level of the vehicle deck. During the maximum height of the flooding, the bottom of that rubber bumper was two inches above the wall of the slip on the Edgartown side.

The slip wall is constructed of vertical sheets of plywood which are eight feet top to bottom. The day after the storm, the low tide was abnormally low. At its lowest point, the top of the rubber bumper was an inch below the bottom of the slip wall.

The difference between high and low tide in a span of less than 30 hours was eight feet, nine inches. That’s a big departure from the government‘s determined tide range of one and a half feet. But that’s what makes life on the waterfront interesting. Things are hardly ever average.

Send Chappy news to peterchappyferry@gmail.com.