this is a clock that uses water to track the tides

Tidal Clock shows the ebb and flow between high and low tide by a rising a falling water level. It works with the help of displacement, Arduino and a little bit of code. 

– Concept Development, Product Design, Art Direction & Photography –

Tidal Clock is designed to bring a sense of the ocean into daily life. It can be set to a local tide chart, or to the tides of a favorite faraway beach. The face of the clock is a shallow chamber. The tide is represented by a body of water that rises and falls in synch with the ebb and flow of the tide from a designated tide chart. The change in water level is caused by displacement. There is a hidden back chamber of water and an Arduino controlled stepper motor that rotates a simple set of gears. The gears are attached to a large volume within the back chamber. As the volume revolves, water is either pushed through or released from the front chamber, causing the water level to fluctuate. 

it can be set to a local tide chart, or the tides of a favorite faraway beach

In its current iteration, the Tidal Clock's code is written to reflect a six hour and thirteen minute cycle from high to low tide. This is the average cycle on the coast of New York and New Jersey. Tide cycles vary slightly over the course of the month due to the gradational pull of the moon. In the next iteration of this project, this variation will be accounted for by using programming to pull the exact tide charts for specific locations.