The results of experimental and numerical research of underwater electrical wire array explosion and generation of extreme state of water using converging strong shock waves with improved efficiency of energy transfer to converging water flow are reported. It is shown that in case of a Cu wire array, the application of the outer metal reflector increases the pressure, density, and temperature of the water in the vicinity of the implosion axis ~1.38, ~1.07 and ~1.33 times, respectively. The influence of the reflector material and it’s radial distance with respect to the wire array on the water parameters in the vicinity of implosion axis was investigated. In addition, it was found that the shock wave reflection at the axis of implosion results in the water boiling and bubbles formation.  Finally, the application of Al wire array explosion with stainless steel reflector results in Al combustion and, respectively, in additional energy delivered to the converging water flow which generates ~540 GPa pressure in the vicinity of the explosion axis.