HOW A TIDE CLOCK WORKS

A tide clock completes a full rotation every 12 hours, 25 minutes, and 14 seconds which is the average time of a full tide cycle.

High tide is marked at the top and low tide at the bottom, with markers around the edge indicating the six hours (62 mins 3sec) between them.  

For optimal accuracy, set the tide clock at a full or new moon when high tide is around 12 noon or midnight. 

As with all clocks, tide clocks experience fluctuations to real world tides. These are hardly noticeable and will eventually even out by themselves. It is advisable not to adjust the clock as it may result in larger discrepancies in future tide predictions.