As a gift for friends that operate tours of Prince William Sound in Alaska, maker ‘rabbitcreek’ decided to make a humongous (4’ diameter) tide clock, controlled by dual Arduino Nanos. 

One Nano operates the adorable—though very large—otter on the clock’s face via a servo and gear reduction setup that holds a kayak paddle to indicate high and low tides. The other board handles the unit’s RGB LED lighting, which shines the appropriate color to indicate the vast swings in daylight time of that region.

An RTC module for each Nano provides accurate timekeeping—thus proper tide and daylight indications—and a small monitor is used for maintenance tasks. It’s a brilliant build that is certain to delight residents and tourists to the area alike!

If you want to know the tide in your area, you could look it up in the paper, on the Internet, or using an app, but this moon-shaped tide clock provides a unique way to see what’s going on at a glance.

The 3D-printed device uses an Arduino Nano for processing, along with an RTC module to keep accurate time—thus accurate tide predictions. A tiny OLED display provides three info screens, selected via a rocket shaped button taking off of the moon’s surface. 

As the clock is meant for education, the moon design will provide a nice reminder of what actually shifts the tides. Arduino code as well as 3D-print files are available on the project’s write-up.

In case you happen to have an ocean nearby, you’re probably familiar with its rising and falling tides. And if mudflat hiking is a thing in your area, you’re also aware of the importance of good timing and knowing when the water will be on its way back. Tide clocks will help you to be prepared, and they are a fun alternative to your usual clock projects. If you’re looking for a starting point, [rabbitcreek] put together an Arduino-based tide clock kit for educational purposes.

If you feel like you’re experiencing some déjà vu here, this indeed isn’t [rabbitcreek]’s first tide clock project. But unlike his prior stationary clock, he has now created a small and portable, coin-cell version to take with you out on the sea. And what shape would better fit than a 3D printed moon — unfortunately the current design doesn’t offer much waterproofing.

For the underlying tide calculation itself, [rabbitcreek] uses just like in his previous project [Luke Miller]’s location-based library for the ubiquitous DS1307 and DS3213 real-time clocks. Of course, if you also want to keep track of other events on your clock, why not set up calendar events for the next rising tide?