Shipworm prevention

特許 権利維持 Shipworms is a name of a group of saltwater clams with long, soft, naked bodies; they are marine bivalve molluscs in the family Teredinidae. They are notorious for boring into (and commonly eventually destroying) wood that is immersed in sea water, including such structures as wooden piers, docks and ships; they drill passages by means of a pair of very small shells borne at one end, with which they rasp their way through.