Disclosed are the usage, preparation, and evaluation of marine antifouling quaternary halide salts containing a cation portion which includes a trialkyltin ether moiety linked to a carbon atom at least two carbon atoms removed from the quaternized nitrogen atom. Taught as providing exceptional marine fouling inhibition are the quaternary salts of benzyl bromide and tertiary amines containing a tributylstannyl ether moiety at least two carbon atoms removed from the amino nitrogen atom with illustrated specific examples including the quaternary salts of benzyl bromide and 2-dimethylamino-2-methyl-1-propyl tributylstannyl ether, benzyl bromide and 1-dimethylamino-2-propyl tributylstannyl ether, benzyl bromide and 2-[N-pyrrolidinyl]ethyl tributylstannyl ether, and benzyl bromide and 2-diisopropylaminoethyl tributylstannyl ether. For antifouling purposes the quaternary salt is blended or dissolved in a resinous polymer component of a marine paint composition applied to an article's surface subsequently to be immersed in ocean water.