The ocean water is always moving. The tides fluctuate twice daily, featuring two high tides (when the water is high and covers more area) and two low tides (when the water retreats and appears low).
This is the result of the gravitational pull of the moon which draws water closer to it. This embrace on the earth creates two tidal bulges on opposite sides across which the earth spins into and out of. Since the earth rotates on its axis every 24 hours, each location will experience the areas of the two bulges and the areas without the two bulges. Hence two high tides and two low tides. The bulges do not move, only the earth moves.
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