Possible Clues:

• "High" or "low" ocean occurrence
• Periodic rise and fall of sea level
• Surge that's bound to be heard
• Not made like this, by the sound of it
• Flow's restricted, we hear
• Turn the flow of this for a change
• Periodic rise and fall of the sea
• One thing that waits for no man
• ''High'' or ''low'' water
• Word with "rip"