The earth's moon is the major cause of the ocean's tides.
Most coastal areas experience two high tides and two low tides each day.
Therefore, tide clocks feature a hand that makes one complete rotation around the face every 12 hours and 25 minutes. For complete accuracy, the clock owner needs to determine these conditions and take them into account. The sun also affects the ocean tides. It generally has about half the influence as the moon because it is so much further away from the earth. When the sun. moon, and earth line up, as they do at the time of a new moon and a full moon, their influences combine to produce high tides that are higher than normal and low tides that are lower than normal.