Which are the three types of tidal currents?

• A. Rotary; Reversing; Hydraulic
• B. Ebb; Flood; Slack
• C. Thermohaline; Wind-Driven; Inshore
• D. Upwelling; Downwelling; Mixing

Answer: (A)

Tidal currents describe the horizontal water movement tied to the rise and fall of the tide, and they cycle through three main states. During the flood current, water is moving toward the shore as the tide rises. After high water, the ebb current carries water seaward as the tide falls. Around the turning points—near high and low water—the current slows to a near stop, creating slack water. These three states—flood, ebb, and slack—are the standard categories used to describe tidal currents because they capture both direction and the characteristic speeds throughout a tidal cycle. The other groupings refer to different physical processes (like rotation in basins, wind- or density-driven circulation, or vertical transport) and don’t describe the three-phase tidal current pattern. So the terms flood, ebb, and slack best describe the three tidal current states.