Method of underwater bonding

A method of bonding underwater substrates comprises a first step in which a two-part composition is applied underwater to at least one substrate and a second step in which the composition is cured underwater. A first part of the composition comprises a cyanoacrylate and a rubber toughening agent composed of reaction products of the combination of ethylene, methyl acrylate, and monomers with carboxylic acid cure sites and/or copolymers of ethylene and methyl acrylate. A second part of the composition comprises a 2-substituted benzothiazole or derivative thereof. The first or second parts also contain a component with at least two (meth)acrylate groups, an anhydride component, and a benzonitrile compound substituted with at least two electron withdrawing groups selected from halogen, NO2, or CN. Preferably, the first part comprises ethyl-2-cyanoacrylate, rubber toughening agent, tetrafluoroisophthalonitrile, and itaconic anhydride or 4-methylphthalic anhydride and the second part comprises 5-chloro-2-methylbenzothiazole and hexanediol diacrylate.