NOVELTY - An antifouling paint composition contains (meth)acrylic-acid metal salt copolymer and triphenyl boron amine complex (I) or pyridine triphenyl boron. The (meth)acrylic-acid metal salt copolymer is obtained by copolymerizing (meth)acrylic acid metal salt and monomer (x) other than zinc methacrylate, zinc acrylate, copper methacrylate and copper acrylate. The (meth)acrylic-acid metal salt is zinc versatate methacrylate, zinc versatate acrylate, zinc naphthenate methacrylate, copper benzoate methacrylate, copper naphthenate methacrylate or copper naphthenate acrylate.    USE - Antifouling paint composition is used for forming antifouling coating film for vessel and underwater structures (all claimed).    ADVANTAGE - The paint composition is environmental-friendly, has excellent antifouling property with respect to organisms adhered to the vessel and underwater structures, and forms coating film having excellent stain resistance for long period of time.    DETAILED DESCRIPTION - An antifouling paint composition contains (meth)acrylic-acid metal salt copolymer and triphenyl boron amine complex of formula (I) or pyridine triphenyl boron. The (meth)acrylic-acid metal salt copolymer is obtained by copolymerizing (meth)acrylic acid metal salt and monomer (x) other than zinc methacrylate, zinc acrylate, copper methacrylate and copper acrylate. The (meth)acrylic-acid metal salt is zinc versatate methacrylate, zinc versatate acrylate, zinc naphthenate methacrylate, zinc naphthenate acrylate, zinc benzoate methacrylate, zinc benzoate acrylate, magnesium benzoate methacrylate, magnesium versatate acrylate, copper versatate methacrylate, copper benzoate methacrylate, copper naphthenate methacrylate or copper naphthenate acrylate.    R1=pyridyl or aromatic group (both optionally substituted), H or 3-30C alkyl.    INDEPENDENT CLAIMS are included for the following:    (1) antifouling coating film;    (2) vessel or underwater structure; and    (3) antifouling method of vessel outer shell or underwater structure.