A fuel cell and a method for using the fuel cell to make electricity, in which the fuel cell has an anode half-cell having an electrocatalytic anode and a liquid anolyte that is substantially isopropanol dissolved in seawater. The fuel cell has a cathode half-cell having an electrocatalytic cathode and a liquid catholyte that is substantially hydrogen peroxide dissolved in slightly acidic seawater. The half-cells share a common proton exchange membrane. When the anode and cathode are in electrical connection the isopropanol is oxidized to carbon dioxide, which is fugitive, and the hydrogen peroxide is reduced to water. In the method, the anolyte and the catholyte, which are in effect the fuel of the fuel cell, are metered and re-circulated as needed to produce the necessary electrical power. The electrocatalytic electrodes are typically comprised of palladium and iridium alloys.