Related Clues:

• Motion of the ocean
• Ebbing thing
• Sand castle destroyer
• Wearing down
• Fab alternative
• High or low phenomenon
• The water's swell
• Wind and rain cause it
• Oceanic phenomenon
• Neap or 66-Down
• Bay of Fundy phenomenon
• Beach cover-up?
• Periodic riser
• Frequent beach visitor
• Gradual decline