What does the face show?

One day of your local tide, drawn as a single line of light across 1,536 points. The curve is the water; the thin red line is now. Left of the line is the twelve hours just past; right of it, the twelve to come. High water crests, low water hollows. You read the next tide the way you read the next hour on a clock face.

How do I set up my sign?

Plug in the single cable. The face shows a setup code and the address set.tidepiece.com. Visit that address and enter your email; we send a sign-in link, no password to invent. Enter the code, then a US ZIP code, and it sets itself to the tide station nearest your water. A NOAA station number works too, if you would rather name the station yourself. Within a minute or two, the face turns to your water.

Does it need Wi-Fi, an app, or charging?

No. The one cable carries both power and the tide. There is no wireless to configure, no app to install, nothing to charge, and no screen to wake. It hangs on the wall and keeps its water, for years, without attention.

Where does the tide come from?

From NOAA, the National Oceanic and Atmospheric Administration’s tide stations, the same predictions mariners use. Your instrument keeps to the station nearest the shore you choose, and keeps itself current from the moment it is plugged in.

Can it keep a different coast than mine? Can I change it later?

Any American shore NOAA charts: the family cottage on Ocracoke, the harbor you sailed from, the beach you grew up on. Change its shore whenever you like at set.tidepiece.com; the face follows within a minute.

What happens if the power or the internet goes out?

The face holds its last tide until the connection returns, then quietly rights itself. After a power outage, the instrument finds its way back to the water on its own. There is nothing to reset.

What is included, and what happens after ten years?

Ten years of the tide, included with the instrument. After ten years, the service renews simply, and we will write to you well before then.

Can it show anything besides the tide?

Time and temperature: the hour, and the current temperature where you are, on one line of light. At set.tidepiece.com you choose whether the instrument keeps the tide, keeps time and temperature, or alternates between the two, and how many minutes each one holds before it turns over. That is the whole of what it displays. It carries no words.

How many Tidepieces are there?

Thirty-one: the number reclaimed, and the number there will ever be. Each instrument began as an American industrial signal display, built in 2011, saved from the landfill, completely refurbished and tested, and reprogrammed with custom code.

Which of the thirty-one is mine?

Yours will tell you. At every power-on, before the tide returns to the face, the instrument states its place in the edition: its own number over thirty-one, in Roman numerals. It holds there a moment, then goes back to the water.

Nothing is engraved on the case and no certificate ships in the box. The number lives in the instrument itself, which is the only place it needs to live. Unplug it, move it, pass it on, and it still knows what it is.