Abstract: An antifouling coating composition having superior antifouling properties and stability over an extended period of time, said composition comprising(A) an antifouling agent composed of (i) 10 parts by weight of a triphenyltiin compound of the formula ##STR1## wherein Y represents --OH, halogen, ##STR2## and (ii) 10 to 60 parts by weight of cuprous oxide and/or cuprous thiocyanate,(B) a resinous vehicle composed of a resin having an acid value of not more than 10 as a main ingredient, and(C) an organic solvent, said resinous vehicle being present in an amount of 6 to less than 10 parts by weight per 10 parts by weight of the triphenyltin compound, said antifouling agent amounting to 37 to 75% by weight based on the weight of the coating composition, and said composition having a pigment volume concentration of 50 to 80% by volume.

Abstract: This invention provides a novel antifouling paint which has excellent storage stability for a long period of time and which affords a coated film having antifouling properties for a long period of time. The paint comprises two components, Component A and Component B, said Component A and said Component B being in separate packages which are mixed before application, wherein Component A contains organotin polymer as antifouling ingredient, and wherein Component B comprises vehicle resin and copper antifoulant.