breakwater, groin, groyne, mole, bulwark, seawall, jetty
['crayfish, crawfish, crawdad, crawdaddy', 'coral reef', 'honeycomb', 'sea slug, nudibranch', 'flatworm, platyhelminth', 'spiny lobster, langouste, rock lobster, crawfish, crayfish, sea crawfish', 'pirate, pirate ship']