Nickel-base alloy 825 is prone to crevice corrosion in seawater. A modified and updated thin-layer cell was used to mimic crevice corrosion, and a new approach to monitor the evolution of the material behavior was developed. The corrosion potential, polarization resistance, and electrolyte resistance were demonstrated to be good indicators to follow the different stages of the crevice-corrosion process. The results were discussed in regard with the cathodic process kinetic. The different tested conditions justify the interest of the methodology developed for this set-up.