Possible Clues:

• Set up around I would for the ebbs and flows
• Sailors' concerns
• In such a setback I would be going in and out
• Such water diets come in and go out again
• Items in a nautical table
• Movements of sea
• Sand-castle wreckers
• The moon affects them
• Destroyers of many small castles
• Do they come in and go out of 1 across?