The Tidal Clock is designed to bring an awareness of the ocean into users’ daily lives, reconnecting city dwellers with their maritime environment. I have lived in New York City for many years and I travel daily between Brooklyn and Manhattan, which are both located on islands, yet I am rarely made aware of the surrounding ocean. The Tidal Clock serves as a pleasant reminder of our closeness to the water. It can be set to one’s local tide chart, or to the tides of a favorite far away beach.
I have been tracking my process of building my initial prototype for the Tidal Clock. The final prototype uses displacement and a stepper motor to change the water level of the clock to reflect the ebb and flow of the tides.
On average the cycle from high to low tide on the coast of New York and New Jersey is 6 hours and 13 minutes. I wrote my code for the stepper motor to reflect this cycle. Moving forward with this project, I would like to use programming to pull the exact tide charts for specified locations. 
Here is a link to my Instructable where you can see details on how I built the prototype. It has been getting great feedback and is even a featured Instructable!
Do you sell these? or know someone that does?