1.  Every 12 hours or so, the seawater rises, and then falls back again. These rises and falls are called the TIDES.  The moon has gravitational power, like the Earth does. Tides happen because the moon's gravity is pulling on the Earth and its oceans.

2.  HIGH TIDE  LOW TIDE

5.  This sequence of high tide and low tide generally happens twice a day everywhere on the planet, approximately every 12 hours and 25 minutes, as the Earth rotates and the moon orbits.  Each tide lasts about 6 hours.