Related Clues:

• Erosion by-product
• Coral buildup
• Atoll, essentially
• Coral construct
• Atoll's makeup
• Ship wrecker
• Shipwreck locale
• Diver's haunt
• Atoll, for one
• Coral Sea hazard
• Coral line
• Marine hazard
• Hazardous obstruction
• Damselfish's home
• Underwater hazard