The results of a study of shock wave (SW) generation by means of underwater electrical wire explosion with different exploding wire configurations and two high-current microsecond and submicrosecond timescale generators are presented. By using aperiodical generator discharge, a ~85% and ~15% of the stored electrical energy was transferred to the exploding wire and energy of the generated water flow, respectively. The energy of the water flow is distributed between its internal (~25%) and kinetic (~75%) energies. It was shown that the exploding wire zigzag configuration, confinement of the SW propagation region, and an increase in the rate of the energy deposition into the exploding wire allow one to increase the SW pressure ges10 times that attained with microsecond timescale straight wire explosion. The averaged thermophysical properties of nonideal and weakly degenerated plasma formed as a result of the wire explosion were obtained and summarized.