Related Clues:

• Skipper's concern
• 6-Across nickname, with "the"
• Neap or ebb, e.g
• Trend metaphor
• Bay level variation
• Ship captain's concern
• Crash diet is affected by the moon
• Certain detergent
• Ebber and flower?
• Ebb or neap
• 'Bama, with 'the'
• Threat to a sand castle
• Sea's rise and fall
• Oceanic flux
• Current influence