An ebb tide occurs when a tidal current moves away from land. Tidal currents moving toward land are called floods. Ebbs and floods are categorized as reversing currents.
When an ebb tide reaches its greatest distance from land, the water in the tide experiences a period of no velocity. This is called slack water. After the slack water stage is over, the water moves back toward land in a flood tide of increasing velocity. Tidal currents are affected by the different phases of the moon. When the moon is full or new, tide velocity increases. A first or third quarter moon weakens tide velocity.